Temporal evolution of chest radiographic appearances in COVID-19 with clinicoradiological associations: a multicentre United Kingdom resident-led study

AIM

To describe the (a) frequency of improving, static, and worsening chest radiograph (CXR) appearances; (b) differences in demographic, initial rudimentary haematological and CXR variables and these patterns; and (c) frequency of different trajectories of serial CXR evolution, in COVID-19 patients presenting consecutively.

MATERIALS AND METHODS

This multicentre retrospective study included all COVID-19 patients admitted from 1-30 April 2020, meeting the inclusion criteria across 24 (blinded) hospitals. Follow-up CXRs on admission, the subsequent (where available), and at 4-8 weeks were scored for the presence of parenchymal opacities across six zones. Three cohorts were defined: improved, static, and/or worsened. The chi-squared and Kruskal-Wallis tests were used to compare demographic, laboratory, and CXR variables. Trajectories of CXR evolution were assessed when all three CXRs were available (226 patients).

RESULTS

Of 452 included patients (median age 66 years, interquartile range 54.3-79, 262 men), 211 (46.7%) improved, 140 (31%) were static, and 101 (22.3%) worsened. Improving patients were more likely younger, with a classic COVID-19 radiograph and higher initial CXR zonal severity scores (both p<0.001), while worsening patients had lower initial lymphocyte counts (p=0.008). The most frequent trajectory was worsened then improved (n=63, 27.9%) followed by static then improved (n=46, 20.4%) and static (n=42, 18.6%).

CONCLUSION

Most patients with COVID-19 during the first wave of the pandemic demonstrated radiographic improvement; these patients were more likely younger with classic COVID-19 appearances and initially more extensive abnormality. Conversely, radiographic deterioration was associated with lower lymphocyte counts. The three most common trajectories were worsening then improvement, static then improvement, and static throughout.

The FOXP3+ Pro-Inflammatory T Cell: A Potential Therapeutic Target in Crohn's Disease

BACKGROUND & AIMS

The incidence of Crohn's disease (CD) continues to increase worldwide. The contribution of CD4+ cell populations remains to be elucidated. We aimed to provide an in-depth transcriptional assessment of CD4+ T cells driving chronic inflammation in CD.

METHODS

We performed single-cell RNA-sequencing in CD4+ T cells isolated from ileal biopsies of patients with CD compared with healthy individuals. Cells underwent clustering analysis, followed by analysis of gene signaling networks. We overlapped our differentially expressed genes with publicly available microarray data sets and performed functional in vitro studies, including an in vitro suppression assay and organoid systems, to model gene expression changes observed in CD regulatory T (Treg) cells and to test predicted therapeutics.

RESULTS

We identified 5 distinct FOXP3+ regulatory Treg subpopulations. Tregs isolated from healthy controls represent the origin of pseudotemporal development into inflammation-associated subtypes. These proinflammatory Tregs displayed a unique responsiveness to tumor necrosis factor-α signaling with impaired suppressive activity in vitro and an elevated cytokine response in an organoid coculture system. As predicted in silico, the histone deacetylase inhibitor vorinostat normalized gene expression patterns, rescuing the suppressive function of FOXP3+ cells in vitro.

CONCLUSIONS

We identified a novel, proinflammatory FOXP3+ T cell subpopulation in patients with CD and developed a pipeline to specifically target these cells using the US Food and Drug Administration-approved drug vorinostat.

Is there a difference in the clinical profile and outcome of women using levonorgestrel IUD for abnormal uterine bleeding and those using it for contraception?: A comparative cross-sectional study

Objective

The most common indications for Levonorgestrel intrauterine device (LNG-IUD) are contraception and management of abnormal uterine bleeding (AUB). This study was conducted with the aim of exploring the differences in the clinical profile and outcome of women using LNG-IUD for contraception and AUB.

Materials and Methods

This was a retrospective comparative cross-sectional study of women who underwent LNG-IUD (52 mg) between 2012 and 2017. Their electronic health records were reviewed until the last documented follow-up or until December 2021.

Results

A total of 235 women had LNG-IUD with an age range of 21 to 62 years and a mean of (37.98 years±6.76). Of these women, 153/235 (65.1%) had it for contraception and 82/235 (34.89%) had it for AUB. The follow-up was 1-94 months with (mean ± SEM) follow-up for the AUB group of (21.48±2.31) months and for contraception group was (20.74±1.76) months (p-value of 0.80). There was a significant difference between the two groups in the age and body mass index (BMI), where women who had LNG-IUD for AUB were older (mean of 42.54±6.49 years, p-value <0.001) and had higher BMI (31.88±7.52 kg/m2, p-value =0.011). All LNG-IUDs that were indicated for contraception were inserted in an outpatient setting. However, 68.3% in the AUB, the insertion was in the operating theater in conjunction with hysteroscopy. After combining both expulsion and removal of LNG-IUD during the follow-up period, there was no significant difference between the 2 groups in the overall retention rate during the follow-up (p-value =0.998).

Conclusion

this study shows that women using LNG-IUD for the management of AUB are older and have a higher BMI compared with those using it for contraception. AUB women experienced more expulsion compared with the contraception group, but there was no difference between the 2 groups in the overall survival/retention of LNG-IUD.

Hypomethylation and Overexpression of Th17-Associated Genes is a Hallmark of Intestinal CD4+ Lymphocytes in Crohn's Disease

BACKGROUND

The development of Crohn's disease [CD] involves immune cell signalling pathways regulated by epigenetic modifications. Aberrant DNA methylation has been identified in peripheral blood and bulk intestinal tissue from CD patients. However, the DNA methylome of disease-associated intestinal CD4+ lymphocytes has not been evaluated.

MATERIALS AND METHODS

Genome-wide DNA methylation sequencing was performed from terminal ileum CD4+ cells from 21 CD patients and 12 age- and sex-matched controls. Data were analysed for differentially methylated CpGs [DMCs] and methylated regions [DMRs]. Integration was performed with RNA-sequencing data to evaluate the functional impact of DNA methylation changes on gene expression. DMRs were overlapped with regions of differentially open chromatin [by ATAC-seq] and CCCTC-binding factor [CTCF] binding sites [by ChIP-seq] between peripherally derived Th17 and Treg cells.

RESULTS

CD4+ cells in CD patients had significantly increased DNA methylation compared to those from the controls. A total of 119 051 DMCs and 8113 DMRs were detected. While hypermethylated genes were mostly related to cell metabolism and homeostasis, hypomethylated genes were significantly enriched within the Th17 signalling pathway. The differentially enriched ATAC regions in Th17 cells [compared to Tregs] were hypomethylated in CD patients, suggesting heightened Th17 activity. There was significant overlap between hypomethylated DNA regions and CTCF-associated binding sites.

CONCLUSIONS

The methylome of CD patients shows an overall dominant hypermethylation yet hypomethylation is more concentrated in proinflammatory pathways, including Th17 differentiation. Hypomethylation of Th17-related genes associated with areas of open chromatin and CTCF binding sites constitutes a hallmark of CD-associated intestinal CD4+ cells.

Atypical Immunoglobulin A Vasculitis in a Pediatric Patient With Ulcerative Colitis

Rates of pediatric inflammatory bowel disease and biologic therapy use continue to rise. Consequently, specialists and generalists should recognize potential complications and side effects. We report the unique case of an adolescent with ulcerative colitis (UC) on vedolizumab presenting with severe abdominal pain, hematochezia, and subsequent purpura. After extensive investigation and a complex clinical course, diagnosis of atypical immunoglobulin A vasculitis was made. This is the first pediatric case of vasculitis in a patient with UC on vedolizumab and only the second reported case overall in UC. This case illustrates the emerging diagnostic challenge of distinguishing inflammatory bowel disease treatment complications from other common pediatric conditions.

Food system actor perspectives on future-proofing European food systems through plant breeding

Crop improvement is a key innovation area in the pursuit of sustainable food systems. However, realising its potential requires integration of the needs and priorities of all agri-food chain stakeholders. In this study, we provide a multi-stakeholder perspective on the role of crop improvement in future-proofing the European food system. We engaged agri-business, farm- and consumer-level stakeholders, and plant scientists through an online survey and focus groups. Four of each group's top five priorities were shared and related to environmental sustainability goals (water, nitrogen and phosphorus efficiency, and heat stress). Consensus was identified on issues including considering existing alternatives to plant breeding (e.g. management strategies), minimising trade-offs, and addressing geographical variation in needs. We conducted a rapid evidence synthesis on the impacts of priority crop improvement options, highlighting the urgent need for further research examining downstream sustainability impacts to identify concrete targets for plant breeding innovation as a food systems solution.

Zika virus alters osteogenic lineage progression of human mesenchymal stromal cells

Arboviruses target bone forming osteoblasts and perturb bone remodeling via paracrine factors. We previously reported that Zika virus (ZIKV) infection of early-stage human mesenchymal stromal cells (MSCs) inhibited the osteogenic lineage commitment of MSCs. To understand the physiological interplay between bone development and ZIKV pathogenesis, we employed a primary in vitro model to examine the biological responses of MSCs to ZIKV infection at different stages of osteogenesis. Precommitted MSCs were infected at the late stage of osteogenic stimulation (Day 7) with ZIKV (multiplicity of infection of 5). We observe that MSCs infected at the late stage of differentiation are highly susceptible to ZIKV infection similar to previous observations with early stage infected MSCs (Day 0). However, in contrast to ZIKV infection at the early stage of differentiation, infection at a later stage significantly elevates the key osteogenic markers and calcium content. Comparative RNA sequencing (RNA-seq) of early and late stage infected MSCs reveals that ZIKV infection alters the mRNA transcriptome during osteogenic induction of MSCs (1251 genes). ZIKV infection provokes a robust antiviral response at both stages of osteogenic differentiation as reflected by the upregulation of interferon responsive genes (n > 140). ZIKV infection enhances the expression of immune-related genes in early stage MSCs while increasing cell cycle genes in late stage MSCs. Remarkably, ZIKA infection in early stage MSCs also activates lipid metabolism-related pathways. In conclusion, ZIKV infection has differentiation stage-dependent effects on MSCs and this mechanistic understanding may permit the development of new therapeutic or preventative measures for bone-related effects of ZIKV infection.

G9a Modulates Lipid Metabolism in CD4 T Cells to Regulate Intestinal Inflammation

BACKGROUND & AIMS

Although T-cell intrinsic expression of G9a has been associated with murine intestinal inflammation, mechanistic insight into the role of this methyltransferase in human T-cell differentiation is ill defined, and manipulation of G9a function for therapeutic use against inflammatory disorders is unexplored.

METHODS

Human naive T cells were isolated from peripheral blood and differentiated in vitro in the presence of a G9a inhibitor (UNC0642) before being characterized via the transcriptome (RNA sequencing), chromatin accessibility (assay for transposase-accessible chromatin by sequencing), protein expression (cytometry by time of flight, flow cytometry), metabolism (mitochondrial stress test, ultrahigh performance liquid chromatography-tandem mas spectroscopy) and function (T-cell suppression assay). The in vivo role of G9a was assessed using 3 murine models.

RESULTS

We discovered that pharmacologic inhibition of G9a enzymatic function in human CD4 T cells led to spontaneous generation of FOXP3+ T cells (G9a-inibitors-T regulatory cells [Tregs]) in vitro that faithfully reproduce human Tregs, functionally and phenotypically. Mechanistically, G9a inhibition altered the transcriptional regulation of genes involved in lipid biosynthesis in T cells, resulting in increased intracellular cholesterol. Metabolomic profiling of G9a-inibitors-Tregs confirmed elevated lipid pathways that support Treg development through oxidative phosphorylation and enhanced lipid membrane composition. Pharmacologic G9a inhibition promoted Treg expansion in vivo upon antigen (gliadin) stimulation and ameliorated acute trinitrobenzene sulfonic acid-induced colitis secondary to tissue-specific Treg development. Finally, Tregs lacking G9a expression (G9a-knockout Tregs) remain functional chronically and can rescue T-cell transfer-induced colitis.

CONCLUSION

G9a inhibition promotes cholesterol metabolism in T cells, favoring a metabolic profile that facilitates Treg development in vitro and in vivo. Our data support the potential use of G9a inhibitors in the treatment of immune-mediated conditions including inflammatory bowel disease.

Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

Successful Management of Maternal Left Atrial Myxoma in Pregnancy

A 29-year-old woman (gravida 3, para 2) presented at 28 weeks+2 days of gestation with a two-months history of dyspnea associated with orthopnea and occasional palpitations. On transthoracic echocardiography, she was diagnosed with a 3.2 × 2.7 cm left atrial myxoma. The patient underwent open surgical resection at 30 weeks of gestation. She had an uneventful postoperative recovery and was discharged on the ninth day. At 41 weeks of gestation, she gave birth by cesarean to a healthy baby of normal weight. Both the mother and the baby were discharged in stable condition.

Ultrasound-guided sub-multifidus block for postoperative pain after lumbar spine surgery - a prospective case series

We describe this series of 15 cases who were scheduled for single level lumbar spine decompression with instrumentation. Here we describe ultrasound (US) guided sub-multifidus block (SMFB). Injections of local anesthetic deep to the multifidus muscle provided reliable block of dorsal rami of spinal nerves at multiple levels in this series. With US the multifidus muscle can be identified both in axial and parasagittal planes. Needle tip is easily visualized beneath the multifidus and medial to transverse process. A good quality analgesia was documented by pain scores. There were no adverse events. This block needs to be compared with routine multimodal analgesia or with the recently describe thoracolumbar interfascial plane block to compare safety and analgesic efficacy.

Differential mRNA expression in ileal and colonic biopsies in irritable bowel syndrome with diarrhea or constipation

Altered mucosal functions are documented in jejunal or colorectal mucosa from patients with irritable bowel syndrome (IBS). Our aim was to quantify ileal, ascending, and rectosigmoid colon mucosal expression of genes in IBS-diarrhea (D) and IBS-constipation (C). Forty-four patients with IBS-D, 30 with IBS-C, and 30 healthy volunteers underwent colonoscopic ileal, ascending, and rectosigmoid colon biopsies. Biopsies were stored in RNA_later at -80 °C, purified with on-column DNase, cDNA libraries prepared from 100-200 ng of total RNA, sequenced on Illumina NovaSeq 6000, and analyzed on Illumina's RTA version 3.4.4. Normalized mRNA expression was obtained using MAP-RSeq bioinformatics pipeline. Differential expressions in the groups (Log2-fold change) were measured using the bioinformatics package edgeR 2.6.2, corrected for false discovery rate (P_ADJ <0.05). There were 30 females with IBS-C and 31 females and 13 males with IBS-D. In IBS-D and IBS-C groups, there were differential expressions of 181 genes in ascending colon and 199 genes in rectosigmoid colon. The majority were gene upregulations in IBS-D with functions reflecting activation of inflammation genes, TRPV1 (visceral hypersensitivity) and neurotransmitters/receptors (specifically purinergic, GABA, and cannabinoid). Although gene differential expressions in the ascending and rectosigmoid colon mucosa of the two groups were different, the diverse upregulated genes involved immune functions, receptors, transmitters, ion channels, and transporters. Conversely, there was reduced expression of PI15 and PI16 genes that inhibit proteases. In patients with IBS-D and IBS-C, differential expressions of genes related to immune, transmitter, nociceptive, protease inhibition, channel, and transporter functions suggest opportunities to reverse the pathobiology and treat patients with IBS.NEW & NOTEWORTHY This study compares gene expression in mucosa of the terminal ileum, right colon, and left colon in patients with diarrhea- or constipation-predominant irritable bowel syndrome (IBS) and contrasts expression between these two disease entities and also between each entity and mucosa from healthy controls. The study shows there is differential expression of genes related to immune, transmitter, nociceptive, ion channel, and transporter functions, as well as reduced serine protease inhibition, in patients with IBS.

Reuniting the Three Sisters: collaborative science with Native growers to improve soil and community health

Before Euro-American settlement, many Native American nations intercropped maize (Zea mays), beans (Phaseolus vulgaris), and squash (Cucurbita pepo) in what is colloquially called the "Three Sisters." Here we review the historic importance and consequences of rejuvenation of Three Sisters intercropping (3SI), outline a framework to engage Native growers in community science with positive feedbacks to university research, and present preliminary findings from ethnography and a randomized, replicated 3SI experiment. We developed mutually beneficial collaborative research agendas with four Midwestern US Native American nations. Ethnographic data highlighted a culturally based respect for 3SI as living beings, the importance it holds for all cultural facets of these Native nations, and the critical impact the practice has on environmental sustainability. One concern expressed by Native growers during ethnographic research was improving soil health-part of the rationale for establishing the 3SI agronomic experiment. To address this, we collaboratively designed a 3SI experiment. After 1 year, 3SI increased short-term soil respiration by 24%, decreased salt-extractable nitrate by 54%, had no effect on soil microbial biomass (but increased its carbon-to-nitrogen ratio by 32%) compared to the average of monoculture crops. The overarching purpose of this collaborative project is to develop a deeper understanding of 3SI, its cultural importance to Native communities, and how reinvigorating the practice-and intercropping in general-can make agroecosystems more sustainable for people and the environment.

Abstract 1944: Prognostic biomarkers for gallbladder cancer: A machine learning approach

Gallbladder cancer (GBC) is one of the deadliest cancers, with a 5-year-survival-rate of less than 5 percent for late-stage disease. The response rate to chemotherapy among GBC patients is generally poor. Recent research has attempted to identify diagnostic, prognostic, and predictive biomarkers, however, currently, no biomarkers can accurately diagnose GBC and predict patients’ prognosis. Integrative analysis of molecular and clinical characterization has not been fully established, and minimal improvement has been made to the survival of these patients, in part due to the heterogeneity of GBC. Machine learning techniques have been proven to empower analysis of big data in oncology, allowing for improvement in the generation of biomarkers to predict patient outcomes. Using machine learning, we can utilize high-throughput RNA sequencing with clinicopathologic data to develop a predictive tool for GBC prognosis. Current predictive models for GBC outcomes often utilize clinical data only, with the highest C-statistic reported being 0.71. C-statistic values over 0.7 generally indicate good models, however 0.8 is the threshold for strong predictive models. We aim to build a superior algorithm to predict overall survival in GBC patients with advanced disease, using machine learning approaches to prioritize biomarkers for GBC prognosis. We have identified over 80 fresh frozen GBC tissue samples from Mayo Clinic Rochester, Dongsan Medical Center in Daegu, Korea, University of the Witwatersrand, in Johannesburg, South Africa, Lithuanian University of Health Science in Vilnius, Lithuania, and University of Calgary in Calgary, Canada, from patients enrolled between 2012 and 2021. We will perform next-generation RNA sequencing on these tissue samples. The patients’ clinical, pathologic and survival data will be abstracted from the medical record uniformly across sites. Feature engineering and dimensionality reduction will be performed. Then random forests, support vector machines, and gradient boosting machines will be applied to train the data. Variable importance will prioritize multi-omic markers. Standard 5-fold cross validation will be used to assess performance of each ML algorithm. If overall survival can be better predicted with the addition patients’ transcriptional sequencing data compared to using clinical profiles alone, we can gain a greater understanding of key biomarkers driving the tumor phenotype.

Citation Format: Linsey Jackson, Loretta Allotey, Valles Kenneth, Gavin Oliver, Asha Nair, Daniel O'Brien, Rondell Graham, Mitesh Borad, Arjun Athreya, Lewis Roberts. Prognostic biomarkers for gallbladder cancer: A machine learning approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1944.

Novel benchmark values for redo liver transplantation – does the outcome justify the effort?

Objective

In the era of organ shortage, redo liver transplantation (reLT) is frequently discussed in terms of expected poor outcome, high cost and therefore wasteful resources. However, there is a lack of benchmark data to reliably assess outcomes after reLT. The aim of this study was to define the ideal reLT case, and to establish clinically relevant benchmark values for best achievable outcome in reLT.

Methods

We collected data on reLT between January 2010 and December 2018 from 22 high volume transplant centers on three continents. Benchmark cases were defined as recipients with model of end-stage liver disease score &lt;=25, absence of portal vein thrombosis, no mechanical ventilation before surgery, receiving a graft from a donor after brain death. In addition, early reLT including those for primary non-function (PNF) were excluded. Clinically relevant endpoints covering intra- and postoperative course were selected and complications were graded by severity using the Clavien-Dindo classification and the comprehensive complication index (CCI). The benchmark cutoff for each outcome was derived from the 75th percentile of the median values of all benchmark centers, indicating the “best achievable” result. To assess the utility of the newly established benchmark values, we analyzed patients who received reLT for PNF (non-benchmark patients).

Results

Out of 1110 reLT 413 (37.2%) qualified as benchmark cases. Benchmark values included: Length of intensive care unit and hospital stay: &lt;=6 and &lt;=24 days, respectively; Clavien-Dindo grade &gt;=3a complications and the CCI at 1 year: &lt;=76% and &lt;=72.2, respectively; in-hospital and 1-year mortality rates: &lt;=14.0% and &lt;=14.3%, respectively. The cutoffs for transplant-specific complications such as biliary complications at 1 year, outflow problems at 1 year and hepatic artery thrombosis at discharge were &lt;=27.3%, &lt;=2.5% and &lt;=4.8%, respectively. Patients receiving a reLT for PNF showed mean outcome values all outside the reLT benchmark values. In-hospital mortality rate was 34.4% and the mean CCI at discharge 68.8.

Conclusion

ReLT remains associated with high morbidity and mortality. The availability of benchmark values for outcome parameters of reLT may serve for comparison in any future analyses of individuals, patient groups, or centers, but also in the evaluation of new therapeutic strategies and principles.

Gut microbial β-glucuronidases regulate host luminal proteases and are depleted in irritable bowel syndrome

Intestinal proteases mediate digestion and immune signaling, while increased gut proteolytic activity disrupts the intestinal barrier and generates visceral hypersensitivity, which in common in irritable bowel syndrome (IBS). However, the mechanisms controlling protease function are unclear. Here we show that members of the gut microbiota suppress intestinal proteolytic activity through production of unconjugated bilirubin. This occurs via microbial β-glucuronidase-mediated conversion of bilirubin conjugates. Metagenomic analysis of fecal samples from patients with post-infection IBS (n=52) revealed an altered gut microbiota composition, in particular a reduction in Alistipes taxa, and high gut proteolytic activity driven by specific host serine proteases compared to controls. Germ-free mice showed 10-fold higher proteolytic activity compared with conventional mice. Colonization with microbiota from high proteolytic activity IBS patients failed to suppress proteolytic activity in germ-free mice, but suppression of proteolytic activity was achieved with colonization using microbiota from healthy donors. High proteolytic activity mice had higher intestinal permeability, a higher relative abundance of Bacteroides and a reduction in Alistipes taxa compared with low proteolytic activity mice. High proteolytic activity IBS patients had lower fecal β-glucuronidase activity and end-products of bilirubin deconjugation. Mice treated with unconjugated bilirubin and β-glucuronidase overexpressing E. coli, which significantly reduced proteolytic activity, while inhibitors of microbial β-glucuronidases increased proteolytic activity. Together, these data define a disease-relevant mechanism of host-microbial interaction that maintains protease homeostasis in the gut.

A70 SEVERE ENTERITIS AND IGA VASCULITIS IN A PEDIATRIC PATIENT WITH ULCERATIVE COLITIS ON VEDOLIZUMAB

Background

Pediatric Ulcerative Colitis (UC) is often unsatisfactorily controlled using ‘conventional’ therapies, thus there has been increasing use of biologic therapies and small molecules to try and improve rates of clinical remission and mucosal healing. Consequently, pediatric gastroenterologists and generalists should be aware of the complications and side effects of these newer molecules. Vedolizumab (VDZ) is a fully humanised anti-integrin therapy that is thought to limit systemic side effects given its gut-specific mechanism.

Aims

Here we report the unique case of a 14-year-old male with UC on vedolizumab presenting with severe abdominal pain, GI bleeding, markedly elevated inflammatory markers and subsequent purpura.

Methods

N/A

Results

A diagnosis of IgA vasculitis (IgAV) was made after extensive imaging, endoscopy and subspecialty consultation. Clinical course was complicated but ultimately responded to high dose steroid treatment without cessation of VDZ.

Conclusions

This case illustrates a potentially independent pathway behind IgAV in a patient on a gut-selective therapy with UC. This is the first pediatric case of vasculitis in a patient with UC on VDZ.

Funding Agencies

None

Comparative evaluation of bond strength of resin cements with and without 10-methacryloyloxydecyl dihydrogen phosphate (mdp) to zirconia and effect of thermocycling on bond strength – An in vitro study

Background

To compare bond strength of resin cements with and without 10-Methacryloyloxydecyl Dihydrogen Phosphate (MDP) to zirconia and evaluate effect of thermocycling on bond strength.

Material and Methods

Standardised test specimens were fabricated as per ADA specification 131. Each Zirconia specimen was mounted in autopolymerzing acrylic resin material. The specimens were divided into 2 groups: Group 1 – specimens bonded with resin cement containing 10-MDP and Group II - specimens bonded with resin cement without 10-MDP. Forty samples of resin cement cylinders were prepared with dimensions of 6mm height and 4mm diameter in line with ADA specification 27 were cured onto the zirconia surface of 10mm x10mm x5mm using customised moulds. Specimens from each cement group were further divided into 2 subgroups: Subgroup A – Specimens that were not thermocycled and Subgroup B – Specimens that were thermocycled. Specimens were then subjected to tensile bond testing by using a Universal testing machine, the data were analysed using independent sample t test for bond strength and paired t test for effect of thermocycling. Statistical analysis used: Data was subjected to normalcy test (Shapiro-wilk test). Data showed normal distribution. Hence parametric test paired t test were applied.

Results

Paired t test revealed that the thermocycling affected the bond strength to zirconia. The highest bond strength was achieved for the resin cement with 10-MDP before thermocycling, whereas the lowest bond strength values were recorded for resin cement without 10-MDP after thermocycling.

Conclusions

Resin cement with 10-MDP showed superior bond strength to Zirconia than resin cement without 10-MDP. Adhesive failure was predominant at Zirconia and resin cement interface. Thermocycling had a significant effect on the bond strength of resin cements to zirconia, showing decreased bond strength.

Key words:10-MDP, Tensile Strength, Zirconia.

Hesitancy around low-dose CT screening for lung cancer

Lung cancer is the leading cause of cancer death worldwide. The absence of symptoms in early-stage (I/II) disease, when curative treatment is possible, results in >70% of cases being diagnosed at late stage (III/IV), when treatment is rarely curative. This contributes greatly to the poor prognosis of lung cancer, which sees only 16.2% of individuals diagnosed with the disease alive at 5 years. Early detection is key to improving lung cancer survival outcomes. As a result, there has been longstanding interest in finding a reliable screening test. After little success with chest radiography and sputum cytology, in 2011 the United States National Lung Screening Trial demonstrated that annual low-dose computed tomography (LDCT) screening reduced lung cancer-specific mortality by 20%, when compared with annual chest radiography. In 2020, the NELSON study demonstrated an even greater reduction in lung cancer-specific mortality for LDCT screening at 0, 1, 3 and 5.5 years of 24% in men, when compared to no screening. Despite these impressive results, a call to arms in the 2017 European position statement on lung cancer screening (LCS) and the widespread introduction across the United States, there was, until recently, no population-based European national screening programme in place. We address the potential barriers and outstanding concerns including common screening foes, such as false-positive tests, overdiagnosis and the negative psychological impact of screening, as well as others more unique to LDCT LCS, including appropriate risk stratification of potential participants, radiation exposure and incidental findings. In doing this, we conclude that whilst the evidence generated from ongoing work can be used to refine the screening process, for those risks which remain, appropriate and acceptable mitigations are available, and none should serve as barriers to the implementation of national unified LCS programmes across Europe and beyond.

Surface Roughness of Titanium Orthopedic Implants Alters the Biological Phenotype of Human Mesenchymal Stromal Cells

Metal orthopedic implants are largely biocompatible and generally achieve long-term structural fixation. However, some orthopedic implants may loosen over time even in the absence of infection. In vivo fixation failure is multifactorial, but the fundamental biological defect is cellular dysfunction at the host-implant interface. Strategies to reduce the risk of short- and long-term loosening include surface modifications, implant metal alloy type, and adjuvant substances such as polymethylmethacrylate cement. Surface modifications (e.g., increased surface rugosity) can increase osseointegration and biological ingrowth of orthopedic implants. However, the localized responses of cells to implant surface modifications need to be better characterized. As an in vitro model for investigating cellular responses to metallic orthopedic implants, we cultured mesenchymal stromal/stem cells on clinical-grade titanium disks (Ti6Al4V) that differed in surface roughness as high (porous structured), medium (grit blasted), and low (bead blasted). Topological characterization of clinically relevant titanium (Ti) materials combined with differential mRNA expression analyses (RNA-seq and real-time quantitative polymerase chain reaction) revealed alterations to the biological phenotype of cells cultured on titanium structures that favor early extracellular matrix production and observable responses to oxidative stress and heavy metal stress. These results provide a descriptive model for the interpretation of cellular responses at the interface between native host tissues and three-dimensionally printed modular orthopedic implants, and will guide future studies aimed at increasing the long-term retention of such materials after total joint arthroplasty. Impact statement Using an in vitro model of implant-to-cell interactions by culturing mesenchymal stromal cells (MSCs) on clinically relevant titanium materials of varying topological roughness, we identified mRNA expression patterns consistent with early extracellular matrix (ECM) production and responses to oxidative/heavy metal stress. Implants with high surface roughness may delay the differentiation and ECM formation of MSCs and alter the expression of genes sensitive to reactive oxygen species and protein kinases. In combination with ongoing animal studies, these results will guide future studies aimed at increasing the long-term retention of widely used titanium materials after total joint arthroplasty.

Regulation of STAT3 signaling in IFNγ and IL10 pathways and in their cross-talk

The pro-inflammatory IFNγ-STAT1 pathway and anti-inflammatory IL10-STAT3 pathway elicit cellular responses primarily utilizing their canonical STATs. However IL10 mediated STAT1 and IFNγ mediated STAT3 activation is also observed, suggesting crosstalk of these functionally opposing signaling pathways can potentially reshape the canonical dynamics both STATs and alter the expression of their target genes. Herein, we measured the dynamics of STATs in response to different doses of IL10 or IFNγ and in their co-stimulation and employed quantitative modeling to understand the regulatory mechanisms controlling signal responses in individual and co-simulation scenarios. Our experiments show, STAT3 in particular, exhibits a bell-shaped dose-response while treated with IFNγ or IL10 and our model quantiatively captured the dose-dependent dynamics of both the STATs in both pathways. The model next predicted and subsequent experiments validated that STAT3 dynamics would robustly remain IL10 specific when subjected to a co-stimulation of both IFNγ and IL10. Genes common to both pathways also exhibited IL10 specific expression during the co-stimulation. The findings thus uncover anovel feature of the IL10-STAT3 signaling axis during pathway crosstalk. Finally, parameter sampling coupled to information theory based analysis showed that bell-shaped signal-response of STAT3 in both pathways is primarily dependent on receptor concentration whereas robustness of IL10-STAT3 signaling axis in co-stimulation results from the negative regulation of the IFNγ pathway.

SeekFusion - A Clinically Validated Fusion Transcript Detection Pipeline for PCR-Based Next-Generation Sequencing of RNA

Detecting gene fusions involving driver oncogenes is pivotal in clinical diagnosis and treatment of cancer patients. Recent developments in next-generation sequencing (NGS) technologies have enabled improved assays for bioinformatics-based gene fusions detection. In clinical applications, where a small number of fusions are clinically actionable, targeted polymerase chain reaction (PCR)-based NGS chemistries, such as the QIAseq RNAscan assay, aim to improve accuracy compared to standard RNA sequencing. Existing informatics methods for gene fusion detection in NGS-based RNA sequencing assays traditionally use a transcriptome-based spliced alignment approach or a de-novo assembly approach. Transcriptome-based spliced alignment methods face challenges with short read mapping yielding low quality alignments. De-novo assembly-based methods yield longer contigs from short reads that can be more sensitive for genomic rearrangements, but face performance and scalability challenges. Consequently, there exists a need for a method to efficiently and accurately detect fusions in targeted PCR-based NGS chemistries. We describe SeekFusion, a highly accurate and computationally efficient pipeline enabling identification of gene fusions from PCR-based NGS chemistries. Utilizing biological samples processed with the QIAseq RNAscan assay and in-silico simulated data we demonstrate that SeekFusion gene fusion detection accuracy outperforms popular existing methods such as STAR-Fusion, TOPHAT-Fusion and JAFFA-hybrid. We also present results from 4,484 patient samples tested for neurological tumors and sarcoma, encompassing details on some novel fusions identified.

COVID-19-associated mucormycosis presenting to the Emergency Department-an observational study of 70 patients

BACKGROUND

Mucormycosis (MM) is a deadly opportunistic fungal infection and a large surge in COVID-19-associated mucormycosis (CAM) is occurring in India.

AIM

Our aim was to delineate the clinico-epidemiological profile and identify risk factors of CAM patients presenting to the Emergency Department (ED).

DESIGN

This was a retrospective, single-centre, observational study.

METHODS

We included patients who presented with clinical features or diagnosed MM and who were previously treated for COVID-19 in last 3 months of presentation (recent COVID-19) or currently being treated for COVID-19 (active COVID-19). Information regarding clinical features of CAM, possible risk factors, examination findings, diagnostic workup including imaging and treatment details were collected.

RESULTS

Seventy CAM patients (median age: 44.5 years, 60% males) with active (75.7%) or recent COVID-19 (24.3%) who presented to the ED in between 6 May 2021 and 1 June 2021, were included. A median duration of 20 days (interquartile range: 13.5-25) was present between the onset of COVID-19 symptoms and the onset of CAM symptoms. Ninety-three percent patients had at least one risk factor. Most common risk factors were diabetes mellitus (70%) and steroid use for COVID-19 disease (70%). After clinical, microbiological and radiological workup, final diagnosis of rhino-orbital CAM was made in most patients (68.6%). Systemic antifungals were started in the ED and urgent surgical debridement was planned.

CONCLUSION

COVID-19 infection along with its medical management have increased patient susceptibility to MM.

RNF20 and RNF40 regulate vitamin D receptor-dependent signaling in inflammatory bowel disease

Despite the identification of several genetic factors linked to increased susceptibility to inflammatory bowel disease (IBD), underlying molecular mechanisms remain to be elucidated in detail. The ubiquitin ligases RNF20 and RNF40 mediate the monoubiquitination of histone H2B at lysine 120 (H2Bub1) and were shown to play context-dependent roles in the development of inflammation. Here, we aimed to examine the function of the RNF20/RNF40/H2Bub1 axis in intestinal inflammation in IBD patients and mouse models. For this purpose, intestinal sections from IBD patients were immunohistochemically stained for H2Bub1. Rnf20 or Rnf40 were conditionally deleted in the mouse intestine and mice were monitored for inflammation-associated symptoms. Using mRNA-seq and chromatin immunoprecipitation (ChIP)-seq, we analyzed underlying molecular pathways in primary intestinal epithelial cells (IECs) isolated from these animals and confirmed these findings in IBD resection specimens using ChIP-seq.The majority (80%) of IBD patients displayed a loss of H2Bub1 levels in inflamed areas and the intestine-specific deletion of Rnf20 or Rnf40 resulted in spontaneous colorectal inflammation in mice. Consistently, deletion of Rnf20 or Rnf40 promoted IBD-associated gene expression programs, including deregulation of various IBD risk genes in these animals. Further analysis of murine IECs revealed that H3K4me3 occupancy and transcription of the Vitamin D Receptor (Vdr) gene and VDR target genes is RNF20/40-dependent. Finally, these effects were confirmed in a subgroup of Crohn's disease patients which displayed epigenetic and expression changes in RNF20/40-dependent gene signatures. Our findings reveal that loss of H2B monoubiquitination promotes intestinal inflammation via decreased VDR activity thereby identifying RNF20 and RNF40 as critical regulators of IBD.

BMI1 maintains the Treg epigenomic landscape to prevent inflammatory bowel disease

FOXP3+ Tregs are expanded within the inflamed intestine of human Crohn's disease, yet FOXP3-mediated gene repression within these cells is lost. The polycomb repressive complexes play a role in FOXP3 target gene regulation, but deeper mechanistic insight is incomplete. We have now specifically identified the polycomb-repressive complex 1 (PRC1) family member, BMI1 in the regulation of a proinflammatory enhancer network in both human and murine Tregs. Using human Tregs and lamina propria T cells, we inferred PRC1 to regulate Crohn's associated gene networks through assays of chromatin accessibility. Conditional deletion of BMI1 in murine FOXP3+ cells led to systemic inflammation. BMI1-deficient Tregs beared a TH1/TH17-like phenotype as assessed by assays of genome wide transcription, chromatin accessibility and proteomic techniques. Finally, BMI1 mutant FOXP3+ cells did not suppress colitis in the adoptive transfer model of human inflammatory bowel disease. We propose that BMI1 plays an important role in enforcing Treg identity in vitro and in vivo. Loss of Treg identity via genetic or transient BMI1 depletion perturbs the epigenome and converts Tregs into Th1/Th17-like proinflammatory cells, a transition relevant to human Crohn's disease associated CD4+ T cells.

Microbial production of omega-3 fatty acids: an overview

The essence of appropriate nutritional intake on a regular basis has a great impact in maintaining fundamental physiological functions and the body metabolism. Considering how pivotal maintaining a nourishing fat diet is to human health, Omega-3 fatty acids have gained a lot of attention in recent times. Omega-3 fatty acids (n-3 FAs) such as eicosapentaenoic acid (EPA) and DHA are considered as essential fatty acids (EFAs) offering enormous nutritional benefits: from playing a major role in the prevention and treatment of a number of human diseases, such as cardiovascular disorders and neurological disorders, to having anti-inflammatory properties, to providing joint support, etc. Hence, their incorporation into our daily diet is of great importance. Also, both EPA and DHA have been shown to be therapeutically significant in treating several infectious diseases. EFAs were initially thought to be marine in origin, produced by fishes. Consequentially, this led to the increase in the industrial extraction of fish oils for meeting the commercial need for of n-3-rich dietary supplements. Although fish oil supplementation met almost all of the dietary demand for EFAs, they did come with a fair share of drawbacks such as undesirable odour and flavour, heavy metal contamination, extinction of fish species, etc. Oleaginous micro-organisms are a promising alternative for the production of a more sustainable, consistent and quality production of n-3 FAs. Thus, the entire review focuses on understanding the eco-friendlier production of n-3 FAs by micro-organisms.

COVID-19: looking beyond the peak. Challenges and tips for radiologists in follow-up of a novel patient cohort

As the coronavirus pandemic evolves, the focus of radiology departments has begun to change. The acute phase of imaging a new disease entity whilst rationalising radiology services in the face of lockdown has passed. Radiologists are now becoming familiar with the complications of COVID-19, particularly the lung parenchymal and pulmonary vascular sequelae and are considering the impact follow-up imaging may have on departments already struggling with a backlog of suspended imaging in the face of reduced capacity. This review from the British Society of Thoracic Imaging explores both the thoracic and extra-thoracic complications of COVID-19, recognising the importance of a holistic approach to patient follow-up. The British Thoracic Society guidelines for respiratory follow-up of COVID-19 will be discussed, together with newly developed reporting templates, which aim to provide consistency for clinicians as well as an opportunity for longer-term data collection.