Co-delivery of HIV pre-exposure prophylaxis (PrEP) and HIV testing among publicly insured adolescents and young adults (AYA) receiving medication for opioid use disorder (MOUD)

BACKGROUND

Low rates of HIV pre-exposure prophylaxis (PrEP) prescribing contribute to the disproportionate burden of HIV in the United States. Among adolescent and young adults (AYA) with opioid use disorder, HIV testing and PrEP co-prescription rates are poorly characterized.

METHODS

We performed a retrospective analysis involving deidentified data from Philadelphia's Medicaid beneficiaries ages 16-29 years who were prescribed medication for opioid use disorder (MOUD) from 2015 to 2020 and continuously Medicaid-enrolled for ≥6 months prior to that prescription. After identifying the presence of a qualifying diagnosis signifying a PrEP indication, we examined the outcome of appropriate PrEP co-prescriptions and HIV testing using generalized estimating equations (GEE) modeling.

RESULTS

We identified 795 AYA Medicaid beneficiaries with 1269 qualified treatment episodes. We calculated a PrEP prescribing rate of 29.47 per 1000 person-years among AYA receiving MOUD. The HIV testing rate was 63.47 per 1000 person-years among AYA receiving MOUD. GEE modeling revealed that individuals receiving methadone were more likely (aOR=2.62, 95% CI=1.06-6.49) to receive HIV testing within 6 months after a PrEP-qualifying diagnosis compared to those receiving other MOUD medications. Those who only saw outpatient behavioral health providers were less likely (aOR=0.48, 95% CI=0.24-0.99) to have received an HIV test within 6 months after the PrEP-qualifying diagnosis compared to those receiving inpatient behavioral health services.

CONCLUSIONS

Co-prescription of PrEP and HIV testing among AYA receiving MOUD was rare in this large urban publicly insured population. Interventions are needed to increase HIV prevention services for this key population of AYA at risk for HIV infection.

Electron Temperature Measurements Using a Two-Filter Soft X-ray Array in VEST

A multichannel soft X-ray (SXR) array has been developed to measure the electron temperature in the Versatile Experiment Spherical Torus (VEST). To estimate electron temperature using the two-filter method applied to SXR intensity, we designed a pinhole camera that has two photodiode arrays with different metallic filters. We also adopted a filter wheel and tested various filter parameters to find the optimal filter set. Through tests, the combination of aluminum and beryllium was found to be the most suitable for the current experimental conditions in VEST. The filtered SXR signals were acquired with a low-noise preamplifier, exhibiting sufficient signal-to-noise ratios for electron temperature estimation based on the intensity ratio of two signals obtained with different filters. The estimated electron temperature from the developed two-filter SXR array showed reasonably matched levels and consistent trends with Thomson scattering measurements. Error contribution from impurity line emission is also discussed.

Impact of Workflow and Educational Interventions on MR Safety in Radiation Oncology

PURPOSE/OBJECTIVE(S)

Magnetic resonance imaging (MRI) is becoming increasingly integrated into radiation oncology (RO) departments with the use of MRI-Linacs and MRI simulation. Due to the number of implants in patients with cancer, adoption of comprehensive patient screening and MR safety workflows in RO is critical. Identifying MR unsafe implants only at the time of MRI simulation leads to same-day cancellations, potentially delaying treatment, and can risk MR safety events (SEs). This quality improvement study evaluated the impact of workflow and educational interventions on MR safety in RO at a single institution.

MATERIALS/METHODS

In an effort to decrease same-day cancellations and improve safety surrounding use of a 3 Tesla MRI simulator at an academic center, three plan-see-do-act (PDSA) cycles were implemented from 4/18/22 - 1/19/23. MR safety oversight for the simulator was provided by a multidisciplinary team, with input from both radiology and RO. PDSA cycle 1 implemented a two-screen functional workflow, adapted from radiology at the same institution. The first screen is completed by the practice coordinator (PC) at the time of scheduling to triage high-risk patients into a work queue (WQ) for further evaluation by the MR safety team. The second screen is performed by the MR technologist (MRT) at the point of care. PDSA cycle 2 involved education for PCs. PDSA cycle 3 was a second PC educational intervention including a visual aide to assist with WQ use. Efficacy was determined by the number of same-day cancellations, patients in the WQ (a measure of the number of patients identified at the initial screen as having an implant), and SEs in each PDSA cycle.

RESULTS

PDSA cycle 1 spanned 56 workdays during which 91 MR simulations were scheduled with 6 cancellations (6.5%). PDSA cycle 2 spanned 84 days during which 173 MR simulations were scheduled with 18 cancellations (10.4%). PDSA cycle 3 spanned 39 workdays and had 94 MR simulations, with 7 cancellations (7.4%). The cancellation rate during each PDSA cycle was 0.11, 0.21, and 0.17 cancellations/day, respectively. The number of patients in the WQ during each PDSA cycle, representing successfully screened high-risk patients, was 0, 0, and 3, respectively. There were no SEs during the study.

CONCLUSION

In this study, an MR safety workflow from radiology was successfully implemented in RO. There were no SEs during the study, but the number of patients successfully screened as high-risk and placed in the WQ increased after repeat PC education. Further increases in WQ use would decrease the demand for implant assessment at point of care, which could decrease burden on the MRT, same day cancellations, and potentially SEs. This will be especially important if case load increases. Future work could expand educational efforts to additional staff.

Differences in coagulation-relevant parameters: Comparing cryoprecipitate and a human fibrinogen concentrate

BACKGROUND

Variable fibrinogen content within cryoprecipitate makes accurate dosing challenging in patients with coagulopathic bleeding, in addition to pathogen transmission risks associated with its administration. Purified and standardized human fibrinogen concentrates (HFCs) represent reliable alternatives. Full cryoprecipitate characterization is required to inform selection of an appropriate fibrinogen source for supplementation therapy.

METHODS

Extended biochemical comparison of pooled cryoprecipitate and HFC (Fibryga, Octapharma) was performed using commercially available assays to determine levels of variability in cryoprecipitate and HFC. In addition to standard procoagulant factors, measurements included activities of platelet-derived microparticles (PMPs) and plasminogen, and levels of fibrin degradation products.

RESULTS

Cryoprecipitate contains lower fibrinogen levels than HFC (4.83 vs.19.73 g/L; p<0.001), translating to approximately half the amount of fibrinogen per standard cryoprecipitate dose (two pools, pre-pooled from five donations each) vs. HFC (2.14 vs. 3.95 g; p<0.001). Factor XIII (FXIII) levels were also lower in cryoprecipitate vs. HFC (192.17 vs. 328.33 IU/dL; p = 0.002). Levels of procoagulants in cryoprecipitate, such as von Willebrand Factor (VWF) and factor VIII (FVIII), were highly variable, as was PMP activity. A standard cryoprecipitate dose contains significantly higher levels of measured plasminogen and D-dimer fragments than a standard HFC dose.

CONCLUSION

The tested HFC is a more reliable fibrinogen and FXIII source for accurate dosing compared with cryoprecipitate. Cryoprecipitate appears considerably less predictable for bleeding management due to wide variation in pro- and anticoagulation factors, the presence of PMPs, and the potential to elevate VWF and FVIII to prothrombotic levels.

Exploring Parametric and Mechanistic Differences between Expi293FTM and ExpiCHO-STM Cells for Transient Antibody Production Optimization

Rapidly producing drug-like antibody therapeutics for lead molecule discovery and candidate optimization is typically accomplished by large-scale transient gene expression technologies (TGE) with cultivated mammalian cells. The TGE methodologies have been extensively developed over the past three decades, yet produce significantly lower yields than the stable cell line approach, facing the technical challenge of achieving universal high expression titers for a broad range of antibodies and therapeutics modalities. In this study, we explored various parameters for antibody production in the TGE cell host Expi293FTM and ExpiCHO-STM with the transfection reagents ExpiFectamineTM and polyethylenimine. We discovered that there are significant differences between Expi293FTM and ExpiCHO-STM cells with regards to DNA complex formation time and ratio, complex formation buffers, DNA complex uptake trafficking routes, responses to dimethyl sulfoxide and cell cycle inhibitors, as well as light-chain isotype expression preferences. This investigation mechanistically dissected the TGE processes and provided a new direction for future transient antibody production optimization.

Complement activation by AAV-neutralizing antibody complexes

Treatment of monogenetic disorders using adeno-associated viral vectors (AAV) is an area of intense interest. AAV is a human pathogen and pre-existing capsid antibodies are prevalent in the population posing a challenge to safety and efficacy of AAV-mediated gene therapies. Here we investigated the risk of AAV-mediated complement activation when sera from a cohort of human donors was exposed to AAV9 capsid. Seropositive donor sera carrying neutralizing antibodies from a previous environmental exposure activated complement when admixed with AAV9 capsids and complement-activation was associated with donors who had higher levels of ant-AAV IgG1 antibodies. These findings were consistent with Mass spectrometry analysis that identified increased binding of immunoglobulins and complement factors when AAV9 capsids were admixed with seropositive sera. Finally, complement activation was abrogated after IgG-depletion using affinity columns or serum pre-treatment with an IgG degrading enzyme. Overall, these results demonstrate an important role of pre-existing neutralizing antibodies in activating complement; a risk that can be mitigated by employing adequate immunosuppression strategies when dosing seropositive patients with vector.

A36 INVESTIGATING TYPE 1 REGULATORY T CELLS AS A THERAPY FOR INFLAMMATORY BOWEL DISEASE USING A MOUSE MODEL OF ACUTE INTESTINAL EPITHELIAL DAMAGE

Background

Inflammatory bowel disease (IBD) affects an estimated 270,000 people in Canada and is rapidly increasing in prevalence. All patients have relapsing disease, and a subset of individuals do not respond to current treatments. Further, there are no approved treatment options in Canada that reverse IBD-induced intestinal fibrosis. We have previously shown type 1 regulatory cells (Tr1s) are capable of suppressing inflammatory macrophages, promote barrier function of human intestinal epithelial cells, and induce differentiation of mucin-producing goblet cells. We hypothesize that Tr1 cells can prevent inflammatory damage and fibrosis in an mouse model of acute gut damage.

Purpose

We hypothesize that Tr1 cells can prevent inflammatory damage and fibrosis in an mouse model of gut damage. Here we evalute the therapeutic potential of Tr1 cells in an model of acute intestinal epithelial damage.

Method

Tr1 cells were isolated and expanded from CD4⁺ CD44^high FOXP3^- cells. Their phenotype was characterized by flow cytometry and cytokine secretion was measured via ELISA. WT B6 mice were given 2% DSS in H₂O for 7 days, followed by H₂O alone for 7 days. Prior to DSS treatment, mice were sub-lethally irradiated to facilitate engraftment, and given I.P. injections of PBS or 0.5 – 2 x 10⁶ Tr1 cells. Mice weights and health scores were recorded daily. At the endpoint, blood, spleen, and mesenteric lymph nodes were analyzed for Tr1 cell engraftment (or lack thereof) for each mouse. Complete white blood counts were performed for each mouse. Additionally, proximal, medial, and distal portions of the ileum were processed for histologic scoring.

Result(s)

Tr1 cells isolated from CD4⁺ CD44^high FOXP3^- cells produce high levels of IL-10 following stimulation (>35,000 pg/ml/1 x 10⁵ cells). Additionally, these cells express high levels of Tr1 markers CD49b and Lag-3. Optimization experiments indicated no significant differences between mice irradiated and given DSS and mice only given DSS (no irradiation). Our results suggest no significant differences in inflammatory cell infiltrate scores between control and Tr1 treated mice. However, gut architecture scores appeared to improve with increasing Tr1 doses. Further, weight change improved with Tr1 treatment, as compared to PBS controls. Interestingly, Tr1 treatment appeared to decrease total eosinophil and neutrophil counts from peripheral blood.

Conclusion(s)

Our initial findings indicate Tr1 adoptive transfer prior to acute damage via DSS improves gut damage and weight loss.

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CIHR

Disclosure of Interest

None Declared

1323 VOLUNTEER-LED ONLINE GROUP EXERCISE FOR OLDER ADULTS: A FEASIBILITY AND ACCEPTABILITY STUDY

Introduction

The health benefits of physical activity for older people are well recognised and include reduction in falls, improvement in frailty status and physical function. Nonetheless, physical inactivity remains a significant problem among older adults. This study aimed to determine the feasibility and acceptability of implementing online volunteer-led group exercise for community-dwelling older adults.

Methods

This pre-post mixed methods study was conducted among older adults attending community social clubs. Eligible participants were aged ≥ 65 years, able to walk independently, and able to provide written consent. The intervention consisted of a once weekly volunteer-led online group chair-based exercise. The primary outcomes were the feasibility and acceptability of the intervention. Secondary outcomes included physical activity levels measured using the Community Health Model Activities Program for Seniors (CHAMPS) questionnaire, functional status (Barthel Index), and health-related quality of life (EQ-5D-5L). Outcomes were measured at baseline and at 6 months. Trials registration: NCT04672200.

Results

Nineteen volunteers were recruited, 15 completed training and 9 were retained (mean age 68 years, 7 female). Thirty participants (mean age 77 years, 27 female) received the intervention and attended 54% (IQR 37-67) of exercise sessions. One minor adverse event was reported. Participants had no significant changes in secondary outcome measures, with a trend towards improvement in physical activity levels. The intervention was acceptable to volunteers, participants, and staff. The seated exercises were perceived as safe, manageable and enjoyable. Volunteers were relatable role models providing positive vicarious experiences that improved participants confidence to exercise within a friendly, non-judgmental environment. Technological issues, or reluctance to learn how to use technology were barriers to the intervention. The social interactions and sense of belonging motivated participation.

Conclusions

Trained volunteers can safely deliver online group exercise for community-dwelling older adults and the intervention was feasible and acceptable to older adults, volunteers and club staff.

Levels of physical activity and sitting time in women with infants, toddlers and preschoolers: a population-based cross-sectional study

OBJECTIVES

Insufficient physical activity (PA) and prolonged sitting time (ST) increase the risk of chronic disease and mortality. Caring for young children can potentially impact maternal PA and sedentary behaviours. The aims of this study were to explore the levels of PA and ST in women with young children (infants, toddlers and preschoolers) and sociodemographic and behavioural factors associated with these.

STUDY DESIGN

This was a population-based cross-sectional study.

METHODS

Survey 5 data collected in 2009 (n = 4290) of the 1973-1978 birth cohort of the Australian Longitudinal Study on Women's Health were used. Multiple linear and logistic regression models were used to examine associations.

RESULTS

In adjusted models, compared with women with preschoolers, women whose youngest child was an infant aged 0-6 months, aged >6-12 months or toddler had lower PA (-321.3 MET.min/week [95% confidence interval (CI) -416.2, -226.4], -147.9 MET.min/week [95% CI -237.6, -58.1] and -106.4 MET.min/week [95% CI -172.3, -40.5]). ST was higher in women whose youngest child was an infant aged 0-6 months (0.48 h/day; 95% CI 0.19, 0.77) but lower with infants aged >6-12 months (-0.33 h/day; 95% CI -0.60, -0.05) and toddlers (-0.40 h/day; 95% CI -0.60, -0.20) than in those with preschoolers. The findings were similar in the logistic model. Sociodemographic and behavioural factors such as occupation and marital status also influenced PA and ST.

CONCLUSIONS

Women with infants and toddlers have lower PA than women with preschoolers. Women are more likely to sit more in the first 6 months after childbirth. These findings can inform resources and intervention development to improve activity levels in women with young children through consideration of the age of the youngest child, sociodemographic and behavioural factors.

Recurrence and outcomes of non-functional pancreatic neuroendocrine tumours post-resection: an Australian retrospective, multicentre cohort study

INTRODUCTION

Pancreatic neuroendocrine tumours (PNETs) are heterogenous entities with variable clinical outlook. The prevalence of PNETs is increasing in Australia. Despite this, data on peri-operative management and post-operative prognosis for Australian patients is scant in the literature.

METHODS

Patients from two tertiary hospitals in Victoria were recruited. Inclusion criteria included patients who underwent curative surgical resection for primary, non-functioning, PNETs without metastases from January 2011 to December 2021. Patients were identified via histopathological reports, CMBS and ICD-10 codes. Data were sourced from Electronic Medical Records, outpatient notes and letters.

RESULTS

Sixty-three patients (34 Male, 29 Female) underwent surgical resection for PNETs. Fifty-three patients (84.1%) had a post-operative complication, and 21 (33.3%) had severe complications. Two patients had disease recurrence. Head PNETs had higher Ki-67% (5.33 vs. 2.72, P = 0.29), and likelihood of nodal spread (9 (36%) vs. 4 (16%), P = 0.054). Pancreatic Head resections were also associated with more frequent ICU admissions (21 (84%) vs. 18 (54.5), P = 0.024), longer ICU stays (4.05 vs. 2.17 days, P = 0.10) and hospital stays (26.76 vs. 8.27 days, P = <0.001).

CONCLUSION

Within the limitations of this study, it demonstrates that surgical resection of PNET carries a significant morbidity with a low rate of recurrence. Additionally, Pancreatic head NETs may be associated with higher grades and increased likelihood of nodal metastases. Considering this, careful patient selection is paramount.

Impacts of fast production of afucosylated antibodies and Fc mutants in ExpiCHO-S™ for enhancing FcγRIIIa binding and NK cell activation

This study has employed mammalian transient expression systems to generate afucosylated antibodies and antibody Fc mutants for rapid candidate screening in discovery and early development. While chemical treatment with the fucose analogue 2-fluoro-peracetyl-fucose during transient expression only partially produced antibodies with afucosylated N-glycans, the genetic inactivation of the FUT8 gene in ExpiCHO-S™ by CRISPR/Cas9 enabled the transient production of fully afucosylated antibodies. Human IgG₁ and murine IgG_2a generated by the ExpiCHOfut8KO cell line possessed a 8-to-11-fold enhanced FcγRIIIa binding activity in comparison with those produced by ExpiCHO-S™. The Fc mutant S239D/S298A/I332E produced by ExpiCHO-S™ had an approximate 2-fold higher FcγRIIIa affinity than that of the afucosylated wildtype molecule, although it displayed significantly lower thermal-stability. When the Fc mutant was produced in the ExpiCHOfut8KO cell line, the resulting afucosylated Fc mutant antibody had an additional approximate 6-fold increase in FcγRIIIa binding affinity. This synergistic effect between afucosylation and the Fc mutations was further verified by a natural killer (NK) cell activation assay. Together, these results have not only established an efficient large-scale transient CHO system for rapid production of afucosylated antibodies, but also confirmed a cooperative impact between afucosylation and Fc mutations on FcγRIIIa binding and NK cell activation.

The long-term cardiac events after coronary bifurcation stenting with second-generation drug-eluting stents in elderly patients are comparable to those of younger patients

Background

Elderly patients undergoing percutaneous coronary intervention (PCI) generally have a high risk of adverse clinical outcomes. We investigated the long-term clinical impact of PCI on coronary bifurcation disease in elderly patients in Korea and Italy.

Methods

From the BIFURCAT (comBined Insights from the Unified RAIN and COBIS bifurcAtion regisTries) data, we evaluated 5,537 patients who underwent PCI for coronary bifurcation disease. The primary outcome was major adverse cardiac events (MACEs), defined as the composite of target vessel myocardial infarction, target lesion revascularisation, and stent thrombosis. Kaplan–Meier estimates and Cox proportional hazard models were used to compare elderly patients (aged ≥75 years) and younger patients (aged &lt;75 years).

Results

A total of 1,415 patients (26%) were aged ≥75 years. Elderly patients were more frequently female, had higher rates of hypertension and chronic kidney disease (CKD), and presented more frequently with left main (LM) disease. After a median follow-up of 2.1 years, MACEs were comparable between elderly and younger patients. In multivariable analysis, old age was not an independent predictor of MACEs (p=0.977). In elderly patients, CKD and LM disease were independent predictors of MACEs, whereas in younger patients, hypertension, diabetes, CKD, reduced left ventricular ejection fraction, LM disease, and two-stent strategy usage were independent predictors.

Conclusions

Elderly patients who underwent coronary bifurcation PCI with second-generation drug-eluting stents demonstrated similar clinical outcomes to those of younger patients. Both CKD and LM disease were independent predictors of MACEs, regardless of age after coronary bifurcation PCI.

Funding Acknowledgement

Type of funding sources: None.

The differential effects of antihypertensive drugs on central blood pressure: nebivolol versus telmisartan (ATD-CBP)

Background

Central blood pressure and central pulse pressure have a better correlation with the risk of cardiovascular disease compared to those of peripheral measurement. In a previous study, a second-generation beta-blocker showed poor CBP-lowering effects. However, the effect on CBP by third-generation beta-blockers is not fully elucidated. Thus, this randomised study investigated whether nebivolol-based hypertension treatment may confer advantages over telmisartan, an angiotensin II receptor-blocker, in reducing CBP.

Methods

This was a prospective, randomised, multicentre, open-label, controlled trial that evaluated 98 hypertensive patients. Patients received either nebivolol- (N=49) or telmisartan-based (N=49) treatment for hypertension for 12 weeks with a target BP of ≤140/80. The primary outcome was the difference in change from baseline central systolic BP (cSBP) after 12 weeks.

Results

There were no significant differences between the two groups in baseline central and peripheral SBP. The mean change in cSBP from baseline (ΔcSBP) was −17.2±3 mmHg for nebivolol group (P&lt;0.001) and −29.9±3 mmHg for telmisartan group (P&lt;0.001). The difference in ΔcSBP between the two groups was significant (12.7mmHg, 95% confidence interval [CI], 4.13 to 21.2; P=0.004). Peripheral SBP (pSBP) decreased less in nebivolol group compared to telmisartan group (−18.0±3 in nebivolol group vs. −26.3±3 in telmisartan group, P=0.032). After adjusting for reduction in pSBP, reduction in cSBP was higher in telmisartan group compared to nebivolol group, as shown by the ratio of changes in cSBP and pSBP (ΔcSBP/ΔpSBP; 0.67 for nebivolol group vs. 1.11 for telmisartan group, P=0.080), albeit without statistical significance.

Conclusions

Nebivolol-based hypertension treatment may have less potent CBP-lowering effects compared to telmisartan. However, larger-scale studies are warranted to further elaborate our findings.

Funding Acknowledgement

Type of funding sources: None.

Effect of an early invasive strategy based on time of symptom onset in patients with non-ST elevation myocardial infarction

Background

A limitation of the current guidelines of the timing of invasive coronary angiography (ICA) for patients with non-ST-segment elevation (NSTE) acute coronary syndrome is based on randomization time. So far, no study has reported the clinical outcomes of invasive strategy timing based on the time of symptom onset. Herein, we aimed to investigate the effect of invasive strategy timing from the time of symptom onset on the 3-year clinical outcomes of patients with NSTE myocardial infarction (MI).

Methods and results

Among 13,104 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health, we evaluated 5,856 patients with NSTEMI. The patients were categorized according to symptom-to-catheter (StC) time (&lt;48 h and ≥48 h). The primary outcome was 3-year all-cause mortality, and the secondary outcome was a 3-year composite of all-cause mortality, recurrent MI, and hospitalization for heart failure. Overall, 3,919 (66.9%) patients were classified into the StC time &lt;48 h group. This group had lower all-cause mortality than the StC time ≥48 h group (7.3% vs. 13.4%, p&lt;0.001). The continuous association of StC time and risk of primary and secondary endpoints showed shorter StC time (reference: 48 h), and lower adjusted hazard ratio reduction was observed. In multivariable analysis, independent predictors of delayed ICA were older age, non-specific symptoms, no use of emergency medical services, no ST-segment deviation, chronic kidney disease, and Global Registry of Acute Coronary Events score &gt;140.

Conclusion

Early invasive strategy based on the StC time improves all-cause mortality in patients with NSTEMI.

Funding Acknowledgement

Type of funding sources: None.

Examining the effect of COVID-19 pandemic on exercise behavior and perceived academic stress among U.S. college students

Objective: The aim of this study was to capture the impact of COVID-19 on exercise behavior in U.S. college students. Exercise behaviors and perceived academic stress were examined from pre-COVID-19 (January-March 2020) and early-COVID-19 (April-July 2020) to continued-COVID-19 times (August-October 2020). Participants: One hundred and thirty-two participants completed the online questionnaires retrospectively. Methods: Two-way analyses of variance were used to examine exercise behaviors and academic stress perception over time between genders. Results: Participants spent much time in sedentary behavior and an increase in academic stress was evident in learning during the early-COVID-19 period. The time spent in sedentary behavior was reduced, but the stress involving coursework remained during the continued-COVID period. The impact of the COVID pandemic was observed to be universal across sex groups. Conclusions: Universities should consider how to support physical and mental health during lockdown and extended closure due to a pandemic.

Group B Streptococcus (GBS) colonisation is dynamic over time, whilst GBS capsular polysaccharides-specific antibody remains stable

Group B Streptococcus (GBS) is a leading cause of adverse pregnancy outcomes due to invasive infection. This study investigated longitudinal variation in GBS rectovaginal colonization, serum and vaginal GBS capsular polysaccharide (CPS)-specific antibody levels. Non-pregnant women were recruited in the UK and were sampled every 2 weeks over a 12-week period. GBS isolates were taken from recto-vaginal swabs and serotyped by polymerase chain reaction. Serum and vaginal immunoglobulin G (IgG) and nasal immunoglobulin A (IgA) specific to CPS were measured by Luminex, and total IgG/A by ELISA. Seventy women were enrolled, of median age 26. Out of the 66 participants who completed at least three visits: 14/47 (29.8%) women that were GBS negative at screening became positive in follow-up visits and 16/19 (84.2%) women who were GBS positive at screening became negative. There was 50% probability of becoming negative 36 days after the first positive swab. The rate of detectable GBS carriage fluctuated over time, although serum, vaginal, and nasal CPS-specific antibody levels remained constant. Levels of CPS-specific antibodies were higher in the serum of individuals colonized with GBS than in non-colonized, but similar in the vaginal and nasal mucosa. We found correlations between antibody levels in serum and the vaginal and nasal mucosa. Our study demonstrates the feasibility of elution methods to retrieve vaginal and nasal antibodies, and the optimization of immunoassays to measure GBS-CPS-specific antibodies. The difference between the dynamics of colonization and antibody response is interesting and further investigation is required for vaccine development.

957 THE USE OF IPADS AS PART OF PERSON CENTERED CARE IN A TEACHING HOSPITAL IN SINGAPORE

The elderly patients are currently the main occupants of acute hospital beds and this trend will likely increase as the world ages. The elderly patients with cognitive issues frequently have behavioural symptoms which may be challenging for the care staff to manage, especially the staff who have not been formally trained in Gerontology. The use of restraints for this group of vulnerable patients should be discouraged as restraints can cause harmful effects.

The use of iPads as a non pharmacological strategy for managing the behavioural symptoms among the elderly in-patients with cognitive issues was effective in reducing agitation, with an improvement in mood and sundown symptoms. The patients were actively and meaningfully engaged with their iPads during therapy.

The nursing staff too, benefited from iPads as a novel therapy for their elderly in-patients with cognitive issues in providing cognitive and social stimulations, which they had no time to provide for. While the patients showed improvement in their behavioural symptoms, the nurses’ stress levels reduced with improved self-reported job satisfaction.

Designing Angstrom-Scale Asymmetric MOF-on-MOF Cavities for High Monovalent Ion Selectivity

Biological ion channels feature angstrom-scale asymmetrical cavity structures, which are the key to achieving highly efficient separation and sensing of alkali metal ions from aqueous resources. The clean energy future and lithium-based energy storage systems heavily rely on highly efficient ionic separations. However, artificial recreation of such a sophisticated biostructure has been technically challenging. Here, a highly tunable design concept is introduced to fabricate monovalent ion-selective membranes with asymmetric sub-nanometer pores in which energy barriers are implanted. The energy barriers act against ionic movements, which hold the target ion while facilitating the transport of competing ions. The membrane consists of bilayer metal-organic frameworks (MOF-on-MOF), possessing a 6 to 3.4-angstrom passable cavity structure. The ionic current measurements exhibit an unprecedented ionic current rectification ratio of above 100 with exceptionally high selectivity ratios of 84 and 80 for K⁺ /Li⁺ and Na⁺ / Li⁺ , respectively (1.14 Li⁺ mol m^-2 h^-1 ). Furthermore, using quantum mechanics/molecular mechanics, it is shown that the combined effect of spatial hindrance and nucleophilic entrapment to induce energy surge baffles is responsible for the membrane's ultrahigh selectivity and ion rectification. This work demonstrates a striking advance in developing monovalent ion-selective channels and has implications in sensing, energy storage, and separation technologies.

Impact of changes in tricuspid regurgitation on clinical outcomes following mitral valve teer compared to guideline-directed medical therapy: a sub-analysis of the COAPT trial

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT)

Background

Prior studies suggest tricuspid regurgitation (TR) diminishes/resolves following mitral valve surgery and thus do not require treatment and may not influence outcomes.

Purpose

  We sought to evaluate the change in TR (ΔTR) and its association with outcomes after transcatheter edge-to-edge repair (TEER) compared with guideline-directed medical therapy (GDMT) in the COAPT trial.

Methods

Patients from the COAPT trial with echo core lab TR assessment at baseline and 30-day follow-up (n = 504) were included and divided into 2 groups: those whose TR worsened (ΔTR-INC) and those with no change or improvement in TR (ΔTR-SAME/DEC).  Two-year composite endpoints of death or heart failure hospitalization (HFH) and the individual components were analyzed, after excluding events occurring within the first 30 days.

Results

ΔTR-SAME/DEC occurred in 430 pts (228 TEER, 202 GDMT) while ΔTR-INC was noted in 74 pts (38 TEER, 36 GDMT) (Figure 1A). From 30 days to 2 years, ΔTR-INC pts had a higher rate of the composite outcome of death or HFH compared with ΔTR-SAME/DEC (p = 0.006, Figure 1B). Both 2-year death (HR 1.52, 95% CI 1.01-2.27; p = 0.04) and HFH (HR 1.52, 95% CI 1.04-2.22; p = 0.03) were associated with ΔTR-INC. Assessed by treatment group (Figure 1C and 1D), the relationship between ΔTR-INC and composite death or HFH was significant in GDMT alone pts (HR 1.86, 95% CI 1.21-2.86) but not in TEER pts (HR 1.33, 95% CI 0.79-2.23), although interaction testing demonstrated consistency between the two treatments  (Pint = 0.31). 

Conclusions

Worsening TR at 30 days occurred in ∼15% of pts in the COAPT trial whether they were treated with TEER or GDMT alone. DTRINC was associated with increased death and HFH during 2-year follow-up. Abstract Figure 1

Formation, collective motion, and merging of macroscopic bacterial aggregates

Chemotactic bacteria form emergent spatial patterns of variable cell density within cultures that are initially spatially uniform. These patterns are the result of chemical gradients that are created from the directed movement and metabolic activity of billions of cells. A recent study on pattern formation in wild bacterial isolates has revealed unique collective behaviors of the bacteria Enterobacter cloacae. As in other bacterial species, Enterobacter cloacae form macroscopic aggregates. Once formed, these bacterial clusters can migrate several millimeters, sometimes resulting in the merging of two or more clusters. To better understand these phenomena, we examine the formation and dynamics of thousands of bacterial clusters that form within a 22 cm square culture dish filled with soft agar over two days. At the macroscale, the aggregates display spatial order at short length scales, and the migration of cell clusters is superdiffusive, with a merging acceleration that is correlated with aggregate size. At the microscale, aggregates are composed of immotile cells surrounded by low density regions of motile cells. The collective movement of the aggregates is the result of an asymmetric flux of bacteria at the boundary. An agent-based model is developed to examine how these phenomena are the result of both chemotactic movement and a change in motility at high cell density. These results identify and characterize a new mechanism for collective bacterial motility driven by a transient, density-dependent change in motility.

Bacteria growing and swimming in soft agar often aggregate to form elaborate spatial patterns. Here we examine the patterns formed by the bacteria Enterobacter cloacae. An unusual behavior of these bacteria is the collective movement of cells after the initial aggregation into a tiny spot. Despite the majority of the cells within an aggregate being immotile at any point in the time, the flux of cells entering and leaving the aggregate, as motility is lost and regained in individual cells, led to a net, collective movement of the aggregate. These spots sometimes run into each other and combine. By looking at the cells within these spots under a microscope, we find that cells within each spot stop swimming. The process of switching back and forth between swimming and not swimming causes the movement and fusion of the spots. A numerical simulation shows that the migration and merging of these spots can be expected if the cells swim towards regions of space with high concentrations of attractant molecules and stop swimming in locations crowded with many cells. This work identifies a novel process through which populations of bacteria cooperate and control the movement of large groups of cells.

Microstructural Evaluation of Phase Instability in Large Bandgap Metal Halide Perovskites

The optoelectronic performance of organic-inorganic halide perovskite (OIHP)-based devices has been improved in recent years. Particularly, solar cells fabricated using mixed-cations and mixed-halides have outperformed their single-cation and single-halide counterparts. Yet, a systematic evaluation of the microstructural behavior of mixed perovskites is missing despite their known composition-dependent photoinstability. Here, we explore microstructural inhomogeneity in (FAPbI₃)_x(MAPbBr₃)_1-x using advanced scanning probe microscopy techniques. Contact potential difference (CPD) maps measured by Kelvin probe force microscopy show an increased fraction of grains exhibiting a low CPD with flat topography as MAPbBr₃ concentration is increased. The higher portion of low CPD contributes to asymmetric CPD distribution curves. Chemical analysis reveals these grains being rich in MA, Pb, and I. The composition-dependent phase segregation upon illumination, reflected on the emergence of a low-energy peak emission in the original photoluminescence spectra, arises from the formation of such grains with flat topology. Bias-dependent piezo-response force microscopy measurements, in these grains, further confirm vigorous ion migration and cause a hysteretic piezo-response. Our results, therefore, provide insights into the microstructural evaluation of phase segregation and ion migration in OIHPs pointing toward process optimization as a mean to further enhance their optoelectronic performance.

Development of postbiotics by whey bioconversion with Enterococcus faecalis M157 KACC81148BP and Lactococcus lactis CAU2013 KACC81152BP for treating periodontal disease and improving gut health

This study developed postbiotics with whey bioconversion product produced by Enterococcus faecalis M157 KACC 81148BP, and mixed whey bioconversion products produced by E. faecalis M157 KACC 81148BP and Lactococcus lactis ssp. lactis CAU2013 KACC 81152BP to alleviate periodontitis (PD) and to improve gut health. The powdered whey bioconversion product (EF) produced by E. faecalis M157 KACC 81148BP, mixed whey bioconversion products (EF+LL) from E. faecalis M157 KACC 81148BP and L. lactis CAU2013 KACC 81152BP, and phosphate-buffered saline (PBS; control) were administered orally to PD-induced rats for 8 wk. Infiltration of inflammatory cells and epithelial proliferation in periodontal tissue were found in control, but the lesions were reduced in PD+EF group (administration of EF to PD-induced rats), and no lesions were observed in PD+EF+LL group (administration of EF+LL to PD-induced rats). The bone loss volumes in PD+EF and PD+EF+LL groups were lower than in control. Cytokine production levels related to inflammation were lower and antioxidative stress markers were higher in PD+EF and PD+EF+LL groups than in control for both periodontal tissue and gut. The ratios of Lactobacillus spp. in gut microbiome of PD+EF and PD+EF+LL groups were higher than in control. These results indicate that the whey bioconversion product produced by E. faecalis M157 KACC 81148BP, and mixed whey bioconversion products produced by E. faecalis M157 KACC 81148BP and L. lactis CAU2013 KACC 81152BP are effective on relieving periodontitis and improving the gut health.

Using group concept mapping software to develop a conceptual framework of left ventricular assist device recipients' experiences

Background

Advanced Heart failure (AHF) carries a high mortality rate. Heart transplantation is one therapeutic option, but low donation rates limits its availability. A left ventricular assist device (LVAD) is an alternative therapy which helps relieve symptoms, while improving prognosis and quality of life. However, lack of donors also means that the LVAD becomes a destination therapy by default.(1) Living with an LVAD requires significant psychological, social and physical adaptation for the recipients' and their families.(2) Patient reported outcome measures (PROMs) are one way of capturing these concerns and ongoing problems. Discussions with a patient and public involvement group found a range of issues not currently captured by available PROMS.

Aim

To develop a conceptual framework which reflects the experiences of LVAD recipients' and evaluate their importance for inclusion in PROMs using a research web platform.

Method

Participants were recruited from a regional transplant centre which covers a wide geographical area in the UK. Ethical approval was obtained and participants were recruited through routine LVAD clinics. Group concept mapping (GCM) is a semi-quantitative mixed methods approach that can be used to capture and quantify recipients' experiences.(3) Groupwisdom concept mapping software was used as the electronic data collection platform.(4) GCM consists of 3 stages: statement generation, thematic statement sorting, and rating statements for importance, relevance and frequency of impact. Multidimensional scaling and hierarchical cluster analysis produces visual representations of recipients' experiences as a points and cluster map, and scoring of statements produces relative importance of items across the clusters.

Results

18 LVAD recipients consented to take part. 101 items and 9 clusters were generated. Clusters represented: Activities; Partner/family dependency; Travel; Mental well-being; LVAD challenges; Equipment and clothing; Physical and cognitive limitations; Restrictions, and LVAD positives. LVAD Positives and LVAD restrictions were rated high for frequency, relevance and importance. Physical and cognitive limitations was rated high for importance and frequency. Equipment was rated high for relevance and frequency, and Challenges was rated high for relevance.

Conclusion

GCM and the online software is a useful tool for developing a conceptual framework and mapping key areas of importance for LVAD recipients, especially, when prioritising important patient reported outcome domains for use in clinical practice, future research and design evolution. Using an electronic platform allowed us to reach participants dispersed over a wide geographical area.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): British Heart FoundationNational Institute for Health Research Cluster Rating Map for Importance

Left ventricular assist device therapy improves severe secondary mitral regurgitation without mitral valve repair

Background

Severe secondary mitral regurgitation (MR) worsens prognosis in patients with medically managed heart failure (HF). In patients treated by left ventricular assist device (LVAD), it is unclear whether severe MR should be corrected at time of LVAD implantation.

Purpose

To evaluate impact of LVAD therapy on severe and non-severe secondary MR over 1 year.

Methods

Retrospective single centre study of consecutive patients who underwent HeartMate (HM)2 or HM3 LVAD implantation between January 2011 and March 2020.

Results

Of 155 patients, 20 were excluded due to LVAD exchange (n=10), mitral valve repair (n=1), or inaccessible pre-LVAD echocardiography (n=9). Based on multiparametric grading, 29/135 patients had severe secondary MR and 106/135 had non-severe secondary MR (including none). Severe MR patients were more often female [10/29 (34%) vs 11/106 (10%); p=0.002] but were of similar age (54±12 vs 55±9 years; p=0.624), size (27±5 vs 27±4 kg/m2; p=1.0), with equivalent renal function (53±22 vs 55±20 ml/min/1.73m2; p=0.641) and median pre-operative NT-proBNP [4076 (IQR 206–5438) vs 4914 (IQR 2706–7518) ng/L; p=0.488]. There were similar proportions of patients with ischaemic aetiology [16/29 (55%) vs 66/106 (62%); p=0.488) and those receiving HM2 [11/29 (38%) vs 32/106 (30%)] and HM3 [18/29 (62%) vs 74/106 (70%); p=0.575] LVAD. Echocardiography before LVAD implantation demonstrated similar left ventricular (LV) size (LV end-diastolic volume: 133±44 vs 118±50ml/m2; p=0.145, end-systolic volume: 107±41 vs 96±59ml/m2; p=0.348) and LV ejection fraction (17±9 vs 17±7%; p=1.0). Severe MR patients had significantly greater (p&lt;0.001) MR by proximal isovolumetric surface area (0.93±0.27 vs 0.60±0.16cm), vena contracta (0.79±0.32 vs 0.57±0.18cm), regurgitant volume (47±25 vs 24±12ml), and fraction (54±15 vs 37±13%). Follow-up (f/u) echocardiography was performed at a median 222 days (range 356 days). Patients who received cardiac transplantation before f/u echocardiography were excluded. Relative severities of MR at f/u were: none = 12 (46%), mild = 8 (31%), moderate = 5 (19%), severe = 1 (4%) amongst patients with severe MR pre-LVAD, and none = 55 (58%), mild = 26 (27%), moderate = 13 (14%), severe = 1 (1%) amongst patients with non-severe MR pre-LVAD. At 1-year, after excluding all patients who underwent cardiac transplantation (severe MR n=4; non-severe MR n=2), rates of HF hospitalisation [5/25 (20%) vs 16/104 (15%); p=0.575] and all-cause mortality [2/25 (18%) vs 22/104 (21%); p=0.129)] were similar, irrespective of pre-LVAD MR severity. No patient who died during follow-up had severe MR prior to death.

Conclusion

LVAD improves severe secondary MR in 96% of cases, resulting in 1-year rates of HF hospitalisation and mortality similar to patients without severe MR pre-LVAD. These data suggest mitral valve surgery at time of LVAD implantation is not warranted.

Funding Acknowledgement

Type of funding sources: None.

Longitudinal evaluation of laboratory-based serological assays for SARS-CoV-2 antibody detection

Serological assays for SARS-CoV-2 infection are now widely available for use in diagnostic laboratories. Limited data are available on the performance characteristics in different settings, and at time periods remote from the initial infection. Validation of the Abbott (Architect SARS-CoV-2 IgG), DiaSorin (Liaison SARS-CoV-2 S1/S2 IgG) and Roche (Cobas Elecsys Anti-SARS-CoV-2) assays was undertaken utilising 217 serum samples from 131 participants up to 7 months following COVID-19 infection. The Abbott and DiaSorin assays were implemented into routine laboratory workflow, with outcomes reported for 2764 clinical specimens. Sensitivity and specificity were concordant with the range reported by the manufacturers for all assays. Sensitivity across the convalescent period was highest for the Roche at 95.2-100% (95% CI 81.0-100%), then the DiaSorin at 88.1-100% (95% CI 76.0-100%), followed by the Abbott 68.2-100% (95% CI 53.4-100%). Sensitivity of the Abbott assay fell from approximately 5 months; on this assay paired serum samples for 45 participants showed a significant drop in the signal-to-cut-off ratio and 10 sero-reversion events. When used in clinical practice, all samples testing positive by both DiaSorin and Abbott assays were confirmed as true positive results. In this low prevalence setting, despite high laboratory specificity, the positive predictive value of a single positive assay was low. Comprehensive validation of serological assays is necessary to determine the optimal assay for each diagnostic setting. In this low prevalence setting we found implementation of two assays with different antibody targets maximised sensitivity and specificity, with confirmatory testing necessary for any sample which was positive in only one assay.

Oxygen Nucleation of MoS2 Nanosheet Thin Film Supercapacitor Electrodes for Enhanced Electrochemical Energy Storage

A direct thin film approach to fabricate large-surface MoS₂ nanosheet thin film supercapacitors using the solution-based diffusion of thiourea into an anodized MoO₃ thin film was investigated. A dense MoS₂ nanosheet thin film electrode (D-MoS₂ ) was obtained when the anodized MoO₃ thin film was processed in a low thiourea solution concentration, whereas a highly porous MoS₂ nanosheet thin film electrode (P-MoS₂ ) was formed at a higher thiourea solution concentration. The charge storage performances of the D-MoS₂ and P-MoS₂ thin films displayed an unusual increase in capacitance on extended cycling, leading to a capacitance as high as around 5-8 mF cm^-2 . X-ray diffraction and cross-sectional microscopy revealed the capacitance enhancements of the MoS₂ supercapacitors are attributable to the nucleation of a new MoS_2-x O_x phase upon cycling. For the D-MoS₂ nanosheet thin film, the formation and growth of the MoS_2-x O_x phase during cycling was accompanied by a volumetric expansion of the MoS₂ layer. For the P-MoS₂ thin film, the nucleation and growth of the MoS_2-x O_x phase occurred in the pores of the MoS₂ layer. The propagation of the MoS_2-x O_x phase also shifted the charge storage process in both films from a diffusion-limited process to a capacitive-dominant process.

Downstream effects of polypathology on neurodegeneration of medial temporal lobe subregions

The medial temporal lobe (MTL) is a nidus for neurodegenerative pathologies and therefore an important region in which to study polypathology. We investigated associations between neurodegenerative pathologies and the thickness of different MTL subregions measured using high-resolution post-mortem MRI. Tau, TAR DNA-binding protein 43 (TDP-43), amyloid-β and α-synuclein pathology were rated on a scale of 0 (absent)-3 (severe) in the hippocampus and entorhinal cortex (ERC) of 58 individuals with and without neurodegenerative diseases (median age 75.0 years, 60.3% male). Thickness measurements in ERC, Brodmann Area (BA) 35 and 36, parahippocampal cortex, subiculum, cornu ammonis (CA)1 and the stratum radiatum lacunosum moleculare (SRLM) were derived from 0.2 × 0.2 × 0.2 mm3 post-mortem MRI scans of excised MTL specimens from the contralateral hemisphere using a semi-automated approach. Spearman's rank correlations were performed between neurodegenerative pathologies and thickness, correcting for age, sex and hemisphere, including all four proteinopathies in the model. We found significant associations of (1) TDP-43 with thickness in all subregions (r =  - 0.27 to r =  - 0.46), and (2) tau with BA35 (r =  - 0.31) and SRLM thickness (r =  - 0.33). In amyloid-β and TDP-43 negative cases, we found strong significant associations of tau with ERC (r =  - 0.40), BA35 (r =  - 0.55), subiculum (r =  - 0.42) and CA1 thickness (r =  - 0.47). This unique dataset shows widespread MTL atrophy in relation to TDP-43 pathology and atrophy in regions affected early in Braak stageing and tau pathology. Moreover, the strong association of tau with thickness in early Braak regions in the absence of amyloid-β suggests a role of Primary Age-Related Tauopathy in neurodegeneration.

PROsetta: An R Package for Linking Patient-Reported Outcome Measures

A common problem when using a variety of patient-reported outcomes (PROs) for diverse populations and subgroups is establishing a harmonized scale for the incommensurate outcomes. The lack of comparability in metrics (e.g., raw summed scores vs. scaled scores) among different PROs poses practical challenges in studies comparing effects across studies and samples. Linking has long been used for practical benefit in educational testing. Applying various linking techniques to PRO data has a relatively short history; however, in recent years, there has been a surge of published studies on linking PROs and other health outcomes, owing in part to concerted efforts such as the Patient-Reported Outcomes Measurement Information System (PROMIS^®) project and the PRO Rosetta Stone (PROsetta Stone^®) project (www.prosettastone.org). Many R packages have been developed for linking in educational settings; however, they are not tailored for linking PROs where harmonization of data across clinical studies or settings serves as the main objective. We created the PROsetta package to fill this gap and disseminate a protocol that has been established as a standard practice for linking PROs.