Choline induced cardiac dysfunction by inhibiting the production of endogenous hydrogen sulfide in spontaneously hypertensive rats

To investigate the exact effects of dietary choline on hypertensive heart disease (HHD) and explore the potential mechanisms, male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were randomly divided into five groups as follows: WKY group, WKY + Choline group, SHR group, SHR + Choline group, and SHR + Choline + NaHS group. In choline treatment groups, rats were fed with 1.3% (w/v) choline in the drinking water for 3 months. The rats in the SHR + Choline + NaHS group were intraperitoneally injected with NaHS (100 micromol/kg/day, a hydrogen sulfide (H2S) donor) for 3 months. After 3 months, left ventricular ejection fraction (LVEF) and fractional shortening (LVFS), the indicators of cardiac function measured by echocardiography, were increased significantly in SHR as compared to WKY, although there was no significant difference in collagen volumes and Bax/Bcl-2 ratio between the two groups, indicating the early stage of cardiac hypertrophy. There was a significant decrease in LVEF and LVFS and an increase in collagen volumes and Bax/Bcl-2 ratio in SHR fed with choline, meanwhile, plasma H2S levels were significantly decreased significantly in SHR fed with choline accompanying by the decrease of cystathionine-gamma-lyase (CSE) activity. Three months of NaHS significantly increased plasma H2S levels, ameliorated cardiac dysfunction and inhibited cardiac fibrosis and apoptosis in SHR fed with choline. In conclusion, choline aggravated cardiac dysfunction in HHD through inhibiting the production of endogenous H2S, which was reversed by supplementation of exogenous H2S donor.

Survey of pharmacy students to assess attitudes toward a career in older adult care

INTRODUCTION

In the United States, the older adult population is growing faster than the geriatrics-trained healthcare workforce. The primary objective of this study was to determine the top factors that increase or decrease pharmacy student interest in seeking a career in geriatrics.

METHODS

A 23-item survey was disseminated to 611 first- through fourth-year pharmacy students. Participants were recruited from two public schools of pharmacy in the United States from February through September 2022. Surveys were administered during class or distributed via email and websites for required courses. Participation was voluntary, and responses were anonymous. Descriptive statistics, independent-samples t-tests, Fisher's exact test, and analysis of variance were used for analysis.

RESULTS

A total of 210 responses were received. Respondents were evenly split between somewhat or extremely interested and somewhat or extremely disinterested in geriatrics. Among those interested, the top factors driving interest were past positive experiences with older adults, interest in deprescribing, and perceived need for geriatrics-trained providers. Among those not interested, the top three factors discouraging interest were emotional impact of death and end-of-life care, disinterest in geriatric syndromes, and perception of inadequate exposure to geriatrics within the curriculum.

CONCLUSIONS

In order to ensure an adequately trained geriatrics workforce for the aging population, it is crucial to intensify efforts to encourage health profession students to pursue careers in geriatric care. Creating opportunities to increase interest and addressing factors that discourage interest may augment the pipeline of pharmacy students wishing to seek a career specializing in older adult care.

Factors Associated with Symptom Persistence in PANS: Part I-Access to Care

Objective: Pediatric acute-onset neuropsychiatric syndrome (PANS) presents with abrupt neuropsychiatric symptoms, often after an immunologic trigger. A 2017 survey of 698 subjects found diagnostic delays to be associated with recurrences, suggesting that timely care impacts course. This secondary analysis explores the impact of barriers to care on symptom persistence. Methods: A 146-question online survey gathered history, symptomatology, intervention, and outcome data from subjects with PANS. Multivariate analyses examined associations between symptom persistence over the entire reported disease course, measured as % days symptom-free over reporting periods averaging approximately 4 years, and access-to-care history, reflected in availability of medical expertise and affordability of care. The impacts of time from symptom onset to treatment and effectiveness of initial antibiotics were also examined. Results: Among the 646 subjects analyzed, greater symptom persistence was associated with longer intervals between symptom onset and treatment (F = 4.43, p = 0.002). Thirty-four percent of subjects with the least symptom persistence (>75% symptom-free days), versus 13% of those with the most (symptoms every day), had been diagnosed by the first practitioner seen (likelihood ratio [L-R] χ2 = 36.55, p < 0.0001, for comparison across all groups). Diagnosis and treatment had not been impeded by lack of access to expertise for 52% of subjects with the least persistent symptoms, versus 22% of those with the most (L-R χ2 = 22.47, p < 0.0001). Affordability had not impacted diagnosis and treatment for 76% of subjects with the least persistent symptoms, versus 42% of those with the most (L-R χ2 = 27.83, p < 0.0001). The subjects whose PANS symptoms resolved with antibiotic treatment of the inciting infection experienced less symptom persistence than others (χ2 = 23.27, p = 0.0001). More persistently symptomatic subjects were more likely to have discontinued intravenous immunoglobulin (IVIG) treatment for access-to-care reasons. Conclusions: Unimpeded access to care for PANS is associated with more symptom-free days over reporting periods averaging approximately 4 years. Difficulty reaching expert providers, missed opportunities for diagnoses, and financial limitations may worsen outcomes. Practitioners, particularly primary providers, should adhere to published diagnostic and treatment guidelines promptly upon presentation.

Factors Associated with Symptom Persistence in PANS: Part II-Presenting Features, Medical Comorbidities, and IVIG Treatment History

Objective: Individuals with Pediatric Acute Onset Neuropsychiatric Syndrome (PANS) experience neuropsychiatric symptoms following an infection or other trigger. Although PANS is typically described as relapsing-remitting, a large community-based 2017 study revealed a range of courses. The present study examined clinical predictors of symptom persistence, measured as % days symptom-free, in this same sample. Methods: A 146-question online survey gathered histories (infections and other triggers, medical and developmental comorbidities), symptomatology, interventions, and outcomes (including school functioning) of PANS patients. Multivariate analyses were applied to examine associations between these variables and % days symptom-free across the disease course. Results: Among the 646 subjects included, significant relationships were found between greater symptom persistence and higher rates of medical comorbidities (especially rashes, headaches, chronic sinusitis, frequent diarrhea, and immune deficiencies), developmental diagnoses, and respondent-perceived developmental lags. Subjects with greater symptom persistence were significantly more likely to report PANS exacerbations associated with infections in close contacts, vaccinations, environmental triggers, and exacerbations of comorbidities and were more likely to report PANS recurrences triggered by Epstein Barr Virus, mycoplasma, and sinus infections. More persistent PANS was also associated with significantly higher frequencies of certain symptoms (sleep disturbance, urinary incontinence, muscle pain, brain fog, sensory defensiveness, irritability, and aggression-related symptoms), less effectiveness of intravenous immunoglobulin in combating symptoms, and more difficulty attending school. Conclusions: Our results suggest high symptom persistence in PANS to be associated with more pervasive medical and neuropsychiatric symptoms. Differences in symptom persistence are associated with both intrinsic (e.g., immune competence) and extrinsic (e.g., infections, treatment) factors. Because extrinsic factors are potentially modifiable, it is critical that providers be aware of current guidelines on PANS evaluation and treatment.

Adapting the investigation of patients on urgent suspected cancer pathway with lower gastrointestinal symptoms across Wales during COVID-19

INTRODUCTION

The COVID-19 pandemic necessitated the introduction of revised diagnostic pathways for assessing urgent suspected cancer (USC) referrals. Combinations of faecal immunochemical testing (FIT) and minimal preparation computed tomography (CT) scans (MPCT) were used to manage referrals and prioritise access to clinical services or invasive tests. The effectiveness of these pathways across Wales is evaluated in this study.

METHODS

All consecutive patients referred from primary care on the USC pathway between 15 March and 15 June 2020 were included to reflect the effect of full lockdown measures. Data collected included demographics, presenting symptom(s), investigations and timelines and patient outcomes up to 90 days following initial referral.

RESULTS

A total of 1,050 patients across eight sites in Wales were included. Of these 1,050 patients, 52.6% were female with median age 68 (21-97) years; 50.5% had first-line clinical review, of which 61.1% were virtual consultations; 49.5% had primary investigations; 26.7% of patients had FIT and 13.1% had MPCT. COVID-response pathways achieved a 29.9% reduction in use of colonoscopy as first-line investigation and 79% of patients avoided face-to-face consultations altogether during this first wave of the pandemic. Overall, 6.8% of USC referrals were diagnosed with colorectal cancer (CRC). Median timescale from diagnosis to treatment for CRC was 65 (4-175) days. The negative predictive value (NPV) for FIT in this cohort was 99.6%. MPCT as the first modality had a NPV of 99.2%.

CONCLUSION

A modified investigation pathway helped maintain cancer diagnosis rates during the pandemic with improved resource utilisation to that used prepandemic.

Factors influencing initial implementation of an online community-based exercise intervention with adults living with HIV: a systems approach

Introduction

Online community-based exercise (CBE) is a digital health intervention and rehabilitation strategy that promotes health among people living with HIV. Our aim was to describe the factors influencing initial implementation of a pilot online CBE intervention with adults living with HIV using a systems approach, as recommended by implementation science specialists.

Methods

We piloted the implementation of a 6-month online CBE intervention and 6-month independent exercise follow up, in partnership with the YMCA in Toronto, Canada. We recruited adults living with HIV who identified themselves as safe to engage in exercise. The intervention phase included personalized exercise sessions online with a personal trainer; exercise equipment; access to online exercise classes; and a wireless physical activity monitor. Two researchers documented implementation factors articulated by participants and the implementation team during early implementation, defined as recruitment, screening, equipment distribution, technology orientation, and baseline assessments. Data sources included communication with participants; daily team communication; weekly team discussions; and in-person meetings. We documented implementation factors in meeting minutes, recruitment screening notes, and email communication; and analyzed the data using a qualitative descriptive approach using a systems engineering method called Cognitive Work Analysis.

Results

Thirty-three adults living with HIV enrolled in the study (n = 33; median age: 52 years; cis-men: 22, cis-women: 10, non-binary: 1). Fifty-five factors influencing implementation, spanned five layers: (i) Natural, including weather and the COVID-19 virus; (ii) Societal, including COVID-19 impacts (e.g. public transit health risks impacting equipment pick-ups); (iii) Organizational, including information dissemination (e.g. tech support) and logistics (e.g. scheduling); (iv) Personal, including physical setting (e.g. space) and digital setting (e.g. device access); and (v) Human, including health (e.g. episodic illness) and disposition (e.g. motivation). The implementation team experienced heightened needs to respond rapidly; sustain engagement; and provide training and support. Additional organizational factors included a committed fitness training and research team with skills spanning administration and logistics, participant engagement, technology training, physical therapy, and research ethics.

Conclusion

Fifty-five factors spanning multiple layers illustrate the complexities of online CBE with adults living with HIV. Initial implementation required a dedicated, rehabilitation-centred, multi-skilled, multi-stakeholder team to address a diverse set of factors.

A16 UNMET HEALTHCARE NEEDS AMONG PEOPLE WITH INFLAMMATORY BOWEL DISEASE: A NATIONAL CROSS-SECTIONAL POPULATION-REPRESENTATIVE STUDY

Background

Inflammatory bowel disease (IBD) is a chronic inflammatory disease primarily affecting the gastrointestinal tract. Despite treatment with the current standards of care, many IBD patients experience relapsing, remitting, and disabling bowel symptoms and significant disease complications. Ensuring patients have adequate access to high quality multidisciplinary healthcare is vital for the short- and long-term wellbeing of IBD patients.

Purpose

(1) Compare unmet healthcare needs of people with and without IBD. (2) Determine whether accessing regular medical care mediates the association between IBD and unmet healthcare needs. (3) Describe the reasons for unmet healthcare needs among people with and without IBD.

Method

We used the 2014 Canadian Community Health Survey, a population-representative national cross-sectional survey conducted by Statistics Canada. Respondents with a non-IBD bowel disorder or aged 18 or younger were excluded. Survey weights were used for descriptive statistics. We used multilevel logistic regression to compare perceived unmet healthcare needs among individuals with and without IBD, clustering by health region and controlling for age, immigration status, race, home ownership, marital status, annual household income, education level, and number of chronic conditions (0, 1, 2+). In a second model, we additionally controlled for having a regular family doctor, having consulted a specialist, and having consulted a psychologist to assess if regularly accessing medical care mediated the association between IBD and unmet healthcare needs. Individuals reporting unmet healthcare needs were asked about the reasons for their unmet healthcare needs. Responses are summarized with weighted percentages, plotted in a bar graph.

Result(s)

Among the 690 IBD and 62,832 non-IBD eligible survey respondents, 16.7% of people with IBD had an unmet healthcare need within the past 12 months, compared with 10.3% of those without IBD (OR 1.39, 95% CI 1.12 to 1.74). Additionally adjusting for regular access to medical care slightly attenuated the association between IBD and unmet healthcare needs (OR 1.29, 95% CI 1.03 to 1.62). Reasons for unmet healthcare needs differed among those with and without IBD (Figure). Specifically, doctors believing that care was unnecessary and the cost of care were more likely to be the reason people with IBD had an unmet healthcare need.

Image

Conclusion(s)

People with IBD are more likely to have an unmet healthcare need that was partially mediated by access to healthcare professionals. Our work highlights the need for further research into the types of unmet healthcare needs experienced by people living with IBD. This underscores the need for multidisciplinary healthcare teams to address the increased burden of unmet healthcare needs in the IBD population.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

G. Postill: None Declared, E. Benchimol Consultant of: Hoffman La-Roche Limited and Peabody & Arnold LLP for matters unrelated to medications used to treat inflammatory bowel disease. Dr. Benchimol has also acted as a consultant for McKesson Canada and the Dairy Farmers of Ontario for matters unrelated to medications used to treat inflammatory bowel disease., J. Im: None Declared, A. Tang: None Declared, E. Kuenzig: None Declared

A177 RISK OF VENOUS THROMBOEMBOLISM IN COVID-19 PATIENTS WITH INFLAMMATORY BOWEL DISEASE: A POPULATION-BASED MATCHED COHORT STUDY

Background

Venous thromboembolism (VTE), is associated with significant morbidity and mortality. Inflammation increases the risk of VTE, and it is a well-recognised complication of both inflammatory bowel disease (IBD) and COVID-19.

Purpose

To compare the risk of VTE among individuals with and without IBD following a positive COVID-19 test.

Method

Using health administrative data from Ontario, Canada we conducted a retrospective matched cohort study.All Ontario residents with a positive SARS-CoV-2 PCR test between January 1,2020 and December 30,2021 who had been diagnosed with IBD prior to their COVID-19 infection (identified using a validated algorithm) were matched to 5 individuals without IBD based on year of birth, sex, mean neighbourhood income quintile, date of positive COVID-19 test, and rural/urban residence. Individuals with a cancer diagnosis in the 5 years prior to their first COVID-19 positive test were excluded. Individuals were followed from positive COVID-19 PCR test until VTE event, death, migration out of Ontario or March 31, 2022.VTEs were identified from emergency department or hospitalization data using ICD-10 codes. Incidence rate of VTEs among individuals with IBD were assessed at 1, 6 and 12 months. Proportional cause-specific hazards models compared the risk of VTEs in people with and without IBD, treating death as a competing risk and controlling for vaccination status (2^nd dose ≥14 days prior to positive COVID-19 test) and a history of VTE (VTE in the 5 years prior to infection).

Result(s)

There were 4293 people with IBD (44% Crohn’s disease, mean age ±SD 46.1±17.2 y) matched to 20,207 with out IBD (mean age 45.3±16.8 y) with a positive SARS-CoV-2 PCR test. Within 1 month of a positive COVID-19 test, the crude incidence rate of VTE in individuals with IBD was 4.77(95%CI, 4.75-4.80) per 100,000 person-days compared to 8.25(95%CI, 8.20-8.30) per 100,000 among people without IBD.Within 6 months, these rates were 1.86(95%CI, 1.86-1.87) and 2.12(95%CI, 2.11-2.12) per 100,000 person-days among people with and without IBD, respectivley. Within 12 months, these rates were 1.59(95% CI, 1.58-1.59) and 1.42(95% CI, 1.42-1.42) per 100,000 person-days among people with and without IBD, respectively.After adjusting for vaccination status and history of VTE there was no difference in the risk of VTE for people with and without IBD (HR 1.08, 95%CI, 0.64 to 1.83).

Conclusion(s)

IBD patients with COVID-19 were not more likely to experience a VTE infection compared with the general popluation. The risk of VTE was highest soon after COVID-19 and declined thereafter.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

None Declared

Antibiotic use for respiratory tract infections among older adults living in long-term care facilities: a systematic review and meta-analysis

BACKGROUND

Antibiotics are commonly prescribed for respiratory tract infections (RTIs) among older adults in long-term care facilities (LTCFs), and this contributes to the emergence of antimicrobial resistance. The objective of this study was to determine the antibiotic prescribing rate for RTIs among LTCF residents, and to analyse the antibiotic consumption patterns with the AwaRe monitoring tool, developed by the World Health Organization.

METHODS

MEDLINE, EMBASE and CINAHL were searched from inception to March 2022. Original articles reporting antibiotic use for RTIs in LTCFs were included in this review. Study quality was assessed using the Joanna Briggs Institute's Critical Appraisal Checklist for Prevalence Data. A random-effects meta-analysis was employed to calculate the pooled estimates. Subgroup analysis was conducted by type of RTI, country, and study start year.

RESULTS

In total, 47 articles consisting of 50 studies were included. The antibiotic prescribing rate ranged from 21.5% to 100% (pooled estimate 69.8%, 95% confidence interval 55.2-82.6%). The antibiotic prescribing rate for lower respiratory tract infections (LRTIs) was higher than the rates for viral and general RTIs. Compared with Italy, France and the USA, the Netherlands had lower antibiotic use for LRTIs. A proportion of viral RTIs were treated with antibiotics, and all the antibiotics were from the Watch group. Use of antibiotics in the Access group was higher in the Netherlands, Norway, Switzerland and Slovenia compared with the USA and Australia.

CONCLUSION

The antibiotic prescribing rate for RTIs in LTCFs was high, and AWaRe antibiotic use patterns varied by type of RTI and country. Improving antibiotic use may require coordination efforts.

Nomogram Based on Clinical and Radiomics Data for Predicting Radiation-induced Temporal Lobe Injury in Patients with Non-metastatic Stage T4 Nasopharyngeal Carcinoma

AIMS

To use pre-treatment magnetic resonance imaging-based radiomics data with clinical data to predict radiation-induced temporal lobe injury (RTLI) in nasopharyngeal carcinoma (NPC) patients with stage T4/N0-3/M0 within 5 years after radiotherapy.

MATERIALS AND METHODS

This study retrospectively examined 98 patients (198 temporal lobes) with stage T4/N0-3/M0 NPC. Participants were enrolled into a training cohort or a validation cohort in a ratio of 7:3. Radiomics features were extracted from pre-treatment magnetic resonance imaging that were T1-and T2-weighted. Spearman rank correlation, the t-test and the least absolute shrinkage and selection operator (LASSO) algorithm were used to select significant radiomics features; machine-learning models were used to generate radiomics signatures (Rad-Scores). Rad-Scores and clinical factors were integrated into a nomogram for prediction of RTLI. Nomogram discrimination was evaluated using receiver operating characteristic analysis and clinical benefits were evaluated using decision curve analysis.

RESULTS

Participants were enrolled into a training cohort (n = 139) or a validation cohort (n = 59). In total, 3568 radiomics features were initially extracted from T1-and T2-weighted images. Age, D_max, D_1cc and 16 stable radiomics features (six from T1-weighted and 10 from T2-weighted images) were identified as independent predictive factors. A greater Rad-Score was associated with a greater risk of RTLI. The nomogram showed good discrimination, with a C-index of 0.85 (95% confidence interval 0.79-0.92) in the training cohort and 0.82 (95% confidence interval 0.71-0.92) in the validation cohort.

CONCLUSION

We developed models for the prediction of RTLI in patients with stage T4/N0-3/M0 NPC using pre-treatment radiomics data and clinical data. Nomograms from these pre-treatment data improved the prediction of RTLI. These results may allow the selection of patients for earlier clinical interventions.

820. Optimal Specimen Source(s) for Carbapenemase-Producing Acinetobacter Colonization Screening

Background

Infection prevention (IP) strategies are implemented to limit the transmission of healthcare-associated infections (HAIs), which are estimated to occur in 1 out of 31 hospitalized patients per day in the United States. Carbapenem-resistant Acinetobacter (CRA) cause HAIs classified as an urgent threat by CDC. When carbapenemase-producing CRA (CP-CRA) are identified, containment strategies are implemented, including screening patients at high risk for colonization with CP-CRA. Point prevalence surveys (PPS) are conducted to assist with HAI outbreak investigations and identify colonized patients.

Methods

Herein, we describe results from culture-based CP-CRA colonization testing of multiple specimen sources (rectal, skin [axilla/groin or groin], respiratory, and/or wound). A total of 744 PPS specimens from 356 patients, across six states, were obtained from February 2019 to May 2021 for CP-CRA colonization screening including 30% (224/744) rectal, 52% (390/744) skin, 10% (73/744) respiratory, and 8% (57/744) wound sources. The specimens were plated onto both non-selective (blood agar) and selective media (MacConkey, ESBL CHROMagar, Acinetobacter CHROMagar), and RT-PCR was performed for detection of the Acinetobacter-specific carbapenemase genes blaOXA-23, blaOXA-24, and blaOXA-58.

Results

Twelve percent (90/744) of specimens, representing 17% (62/356) of patients, were positive for detection of blaOXA-23 and/or blaOXA-24 CP-CRA. The majority (96%) of CP-CRA harbored blaOXA-24. Of the 62 colonized patients, 52% (32/62) had more than one collection source and 47% (15/32) of those had more than one source positive for CP-CRA. There was no consensus regarding a single source type across positive specimens. However, rectal or skin swab collection alone would potentially miss 2% (4/163) or 8% (14/186) of positive specimens, respectively.

Conclusion

These data suggest that rectal or skin source collection alone could be sufficient for detection of CP-CRA. Overall, multiple factors should be considered to guide the source(s) for CP-CRA specimen collection, such as infection type, regional prevalence, patient factors, and/or IP gap(s) within a facility.

Disclosures

All Authors: No reported disclosures

Insight into biosorption of heavy metals by extracellular polymer substances and the improvement of the efficacy: a review

Heavy metals are continuously released into aquatic environments in which they accumulate. This phenomenon endangers public health because heavy metals accumulate along the food chain. However, conventional remediation methods are inefficient, expensive and yield toxic intermediate products, which adversely affect the environment. The discovery of green bio-adsorbents such as microbial extracellular polymer substance (EPS) has quickly attracted considerable worldwide attention because of their low cost, high removal efficiency of heavy metals and industrial availability. Hence, this review considers the sources, hazards and treatment methods of heavy metals pollution, particularly the biosorption mechanism of EPS to heavy metals and the influencing factors of the bio-adsorption process, which are significant in the efficient removal of heavy metals-containing wastewater treatment. This review also focuses on strengthening the process of EPS adsorption of heavy metals, which can further contribute to heavy metals removal. Finally, it has been proposed that improving the yield, stability, selectivity and recoverability of EPS is the key direction of further research.

Phase I/II trial of palbociclib, pembrolizumab and letrozole in patients with hormone receptor-positive metastatic breast cancer

BACKGROUND

CDK4/6 inhibitors modulate immune response in breast cancer. This phase I/II trial was designed to test the safety and efficacy of palbociclib, pembrolizumab and letrozole in women with hormone receptor positive (HR⁺) human epidermal growth factor receptor 2 negative (HER2^-) metastatic breast cancer (MBC).

PATIENTS AND METHODS

Women with stage IV HR⁺ HER2^- MBC were enrolled and treated with palbociclib, pembrolizumab and letrozole. Primary end-points were safety, tolerability and efficacy.

RESULTS

Between November 2016 and July 2020, 23 patients were enrolled with 20 evaluable for response, including 4 patients in cohort 1 and 16 patients in cohort 2. Cohort 1 median age was 48 years (33-70) and cohort 2 median age was 55 (37-75). Cohort 1 closed early due to limited accrual. Grade III-IV adverse events were neutropenia (83%), leucopaenia (65%), thrombocytopenia (17%) and elevated liver enzymes (17%). In cohort 1, 50% achieved a partial response (PR) and 50% had stable disease (SD). In cohort 2, 31% achieved complete response (CR), 25% had PR and 31% had SD by Response Evaluation Criteria in Solid Tumours version 1.1. Median progression-free survival was 25.2 months (95% confidence interval [CI] 5.3, not reached) and median overall survival was 36.9 months (95% CI 36.9, not reached) in cohort 2 with a median follow-up of 24.8 months (95% CI 17.1, not reached). A correlative immune biomarker analysis was published separately.

CONCLUSION

The combination of palbociclib, pembrolizumab and letrozole is well tolerated, and a complete response rate of 31% was identified in HR⁺ MBC patients who received this combination as front-line therapy. Confirmatory trials are required to better understand the immune-priming effects of CDK4/6 inhibitors.

Nutrition and Physical Activity Clinical Practice Guidelines for Older Adults Living with Frailty

Background: We developed clinical practice guidelines to provide health care providers with evidence-based recommendations for decisions related to the effective management of frailty and pre-frailty using nutrition and physical activity interventions. Methods: We based the recommendations on two systematic reviews with meta-analyses. Nutrition, physical activity, and combined nutrition and physical activity interventions for adults ≥65y were considered if study populations were identified as frail using a frailty tool or assessment. Risk of bias and certainty of evidence were evaluated. We included physical outcomes, mobility, frailty, cognitive function, activities of daily living, falls, quality of life, diet quality, energy/fatigue levels, health services use, and caregiver outcomes. Results: Overall, mobility improvements were moderate with nutritional strategies that optimize dietary intake, various types of physical activity interventions, and interventions that combine nutrition and physical activity. Physical outcomes, such as body mass and muscle strength, improved moderately with nutritional strategies and interventions that combined nutrition with physical activity. Frailty status improved with multi-component physical activity interventions. Strong recommendations include optimizing dietary intake, performing physical activity, and adopting interventions that combine nutrition and physical activity. We strongly recommend various types of physical activity including muscle strengthening activities, mobilization or rehabilitation exercises, and multi-component physical activity interventions. Interpretation: Tailored nutrition and physical activity interventions based on individual goals and health status are associated with improved clinical and physical outcomes. While the recommendations facilitate shared decision-making, we identified sparse application of validated frailty assessments and lack of standardized research outcomes as critical gaps in knowledge.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Pelvic floor muscle training: mechanisms of action for the improvement of genitourinary syndrome of menopause

Objective: This study aims to investigate the mechanism of action of pelvic floor muscle training (PFMT) for the improvement of the signs and symptoms of genitourinary syndrome of menopause (GSM) in postmenopausal women with GSM and urinary incontinence (UI).Methods: Twenty-nine women were included in the secondary analysis of a single-arm feasibility study. Using color Doppler ultrasound, the peak systolic velocity, time-averaged maximum velocity, and pulsatility index of the internal pudendal and dorsal clitoral arteries were measured at rest and after a pelvic floor muscle (PFM) contraction task. PFM function was assessed by dynamometry, and vulvovaginal tissue elasticity was measured using the Vaginal Atrophy Index.Results: PFMT significantly improved blood flow parameters in both arteries (p < 0.05) and significantly increased the speed of PFM relaxation after a contraction (p = 0.003). After the intervention, a marginally significant decrease in PFM tone was observed, as well as an increase in PFM strength (p = 0.060 and p = 0.051, respectively). Finally, improvements in skin elasticity and introitus width were observed as measured by the Vaginal Atrophy Index (p < 0.007).Conclusion: Our findings suggest that PFMT improves blood flow in vulvovaginal tissues, PFM relaxation capacity, and vulvovaginal tissue elasticity in postmenopausal women with GSM and UI.

Very high rate of false positive biochemical results when screening for pheochromocytoma in a large, undifferentiated population with variable indications for testing

OBJECTIVE

Pheochromocytoma/Paraganglioma (PPGL) is a rare tumor with non-specific presentations overlapping common entities like anxiety, hypertension, acute illness and episodic "spells." Assessment of urine normetanephrine or metanephrine (UNM-UMN) in real-life, where PPGL is very rare and PPGL mimics extremely common, may show overlap in results with loss of specificity depending on the reference range. We determined the extent to which UNM-UMN are high in people undergoing screening for PPGL.

DESIGN AND METHODS

Retrospective review of all UNM-UMN performed in a central lab serving Southern Alberta over 8 years.

RESULTS

After excluding pediatric ages and patients with CKD, there were 12,572 unique patients with 14,383 measures of UNM-UMN. 85 patients (0.7%) had markedly high UNM-UMN compatible with likely PPGL. Depending on the age category (in decades), 10-22% of all UNM results were above the upper reference limit(URL), particularly between ages of 40-60. Less than 3% had elevations in both UNM and UMN. Of those with high UNM, 99% were less than 3-fold the URL. Based on the population data, a potential new reference range for UNM is suggested, which may be more appropriate to the types of patient who undergo this form of testing.

CONCLUSIONS

There is an extraordinarily high prevalence of high UNM seen in real-life use of the test. However, the vast majority of high UNM are unlikely to be PPGL given the disease rarity and the massive number of tests ordered. This suggests the current laboratory URL may be too low (poor specificity) and/or the reference range may not be appropriate to the type of patient being screened for PPGL. Depending on the frequency of use of any screening test in a population, if the disease is rare and the specificity of the test is poor, a high rate of false positive results will be expected.

How Well Can You Tailor the Charge of Lipid Vesicles?

Knowledge and control of surface charge or potential is important for tailoring colloidal interactions. In this work, we compare widely used zeta potential (ζ) measurements of charged lipid vesicle surface potential to direct measurements using the surface force apparatus (SFA). Our measurements show good agreement between the two techniques. On varying the fraction of anionic lipids dimyristoylphosphatidylserine (DMPS) or dimyristoylphosphatidylglycerol (DMPG) mixed with zwitterionic dimyristoylphosphatidylcholine (DMPC) from 0 to 100 mol % we observed a near-linear increase in membrane surface charge or potential up to 20-30 mol % charged lipids beyond which charge saturation occurred in physiological (high) salt conditions. Similarly, in low salt concentrations, a linear increase in charge/potential was found but only up to ∼5-10 mol % charged lipids beyond which the surface charge or potential leveled off. While a lower degree of ionization is expected due to the lower dielectric constant (ε ∼ 4) of the lipid acyl chain environment, increasing intramembrane electrostatic repulsion between neighboring charged lipid head groups at higher charge loading contributes to charge suppression. Measured potentials in physiological salt solutions were consistent with predictions using the Gouy-Chapman-Stern-Grahame (GCSG) model of the electrical double layer with Langmuir binding of counterions, but in low salt conditions, the model significantly overestimated the surface charge/potential. The much lower ionization in low salt (maximum ∼1-2% of total lipids ionized) instead was consistent with counterion condensation at the bilayer surface which limited the charge that could be obtained. The strong interplay between membrane composition, lipid headgroup ionization, electrolyte concentration, and solution pH complicates exact prediction and tuning of membrane surface charge for applications. However, the theoretical frameworks used here can provide guidelines to understand this interplay and establish a range of achievable potentials for a system and predict the response to triggers like pH and salt concentration changes.

Development and validation of a nomogram to predict the risk of occult cervical lymph node metastases in cN0 squamous cell carcinoma of the tongue

We have explored the relations between clinicopathological features and cervical lymph node metastases (LNM) in patients with cN0 squamous cell carcinoma (SCC) of the tongue, and developed and validated a nomogram for predicting the risk of their development. Clinical data on 230 patients with cN0 SCC of the tongue who had had primary extended excision and lymph node dissection of the neck were collected retrospectively. They were divided into a development cohort and a validation cohort in a 4:1 ratio. Logistic regression analysis was used to assess the risk factors of cervical LNM in patients in the development cohort, and a nomogram was established to predict the risk of such nodes. In the validation cohort, the predictive performance and compliance of the model were evaluated using the consistency index (C-index) and calibration curve, and the clinical value was evaluated by decision curve analysis. Of the 230 patients, 60 had cervical LNM, of which 60 were invaded (26%). Analysis of the development cohort showed that the site of the primary lesion, depth of invasion, size of the tumour, and histopathological grade were included in the prediction model, which was validated in the validation cohort. Consistency was high (C-index=0.846), calibration good, and it was clinically valuable. The nomogram could be used to predict the probability of occult cervical LNM before operation in patients with stage cN0 SCC of the tongue. It could also be used as a reference tool for dissection of cervical nodes and a communication tool between the doctor and the patient.

82. First 5 Years of Experience with the Illinois Extensively Drug-Resistant Organism (XDRO) Registry and Implementation of Automated Alerting

Background

The Illinois XDRO Registry was created in November 2013 as an information system for XDROs; currently, the registry includes carbapenem-resistant Enterobacteriaceae (CRE), carbapenemase-producing Pseudomonas aeruginosa, and Candida auris. All Illinois healthcare facilities can manually query the registry at the time of admission to assess patients’ prior colonization status. A subset of facilities, mainly hospitals, participate in the registry’s automated querying process; alerts are generated automatically and sent via email, page, or text to infection preventionists at the time of patient admission.

Methods

We assessed counts of XDRO report submissions and total queries (manual and automated) over time, by organism. Facilities achieved automated alerts by sending a near-real-time feed of inpatient admission data (patient name and date of birth) to Illinois Department of Public Health (IDPH) via one of the three connection types: direct (data sent directly to IDPH), vendor (data sent via vendor software), and syndromic surveillance (existing syndromic surveillance data adapted for registry).

Results

In total, 6,445 unique patients (11,258 total reports) from 213 facilities have been reported to the XDRO registry (counts by organism type, Table). The registry has been manually queried 39,678 times by 232 facilities. Seventy-five facilities have achieved automation of alerting; the types of data connections used were direct (N = 56), vendor (N = 18), and syndromic surveillance (N = 1). In total, 5,344 automated alerts have been sent for 1,555 unique patients. Automated alerts per month have increased over time (P < 0.001, Figure). Infection preventionists reported feedback on 3,008 CRE alerts via a website questionnaire; among 1176 first alerts/patient/facility, 49% of patients’ XDRO status were previously unknown to the facility, and 33% were not in contact precautions at the time of alert.

Conclusion

The XDRO registry, originally focused on CRE, successfully expanded to include emerging XDRO threats such as Candida auris and is poised for rapid response to emerging threats. The registry’s adaptable reporting structure and expanding automation have enabled it to deliver an increasing number of actionable infection-control alerts over time.

Disclosures

All Authors: No reported Disclosures.

2852. Epidemiology of Emerging Carbapenemase-Producing Organisms (CPO) in Chicago, Illinois, 2013–2018

Background

Emerging CPO in the Chicago area poses clinical and infection control challenges across the spectrum of care. Since November 2013, CPO are reportable to the Illinois’ Extensively Drug-resistant Organism (XDRO) registry. We examined trends in mechanism of resistance (MOR) among CPO reported through December 2018.

Methods

MOR reported into the XDRO registry were identified by clinical laboratories performing molecular methods on routine clinical cultures, by public health laboratories during point prevalence surveys (PPS) in response to clusters and as part of a project to assess CPO prevalence in high-risk Chicago area healthcare settings. Chicago patients with known MOR other than Klebsiella pneumoniae carbapenemase (KPC) are investigated by Chicago Department of Public Health (CDPH) to implement containment strategies and identify risk factors within 6 months of culture date.

Results

MOR was identified in 40% (1,216/3,587) of CPO-positive specimens collected from unique Chicago patients; 87% were KPC, 7% New Delhi metallo-β-lactamase (NDM), 5% Verona integron-mediated metallo-β-lactamase (VIM), 0.6% OXA-48-type carbapenemases, and 0.01% Imipenemase metallo-β-lactamase (IMP) (figure). Since 2017, 15 patients with CPO expressed more than one MOR; 14 were identified during PPS at ventilator capable skilled nursing facilities (vSNF) or long-term acute care hospitals (LTACH), and one was hospitalized in India. Among 156 patients with non-KPC CPO, the median age was 64 years (range, 20–97), 107 (69%) were identified from rectal screening and 49 (31%) were from clinical specimens, most of which were urine 23 (47%) or blood 6 (12%). Among 134 patients with risk factor history, 64% had history of tracheostomy (Table 1). Among 113 patients without documented travel outside of the United States, all stayed overnight at an Illinois healthcare facility; 62% stayed in a vSNF and 24% in an LTACH within 6 months of identification (Table 2).

Conclusion

We have increasingly detected non-KPC CPO in Chicago; however, estimates of prevalence are limited by lack of systematic surveillance and molecular testing. The high proportion of CPO patients without travel who stayed in vSNF or LTACH underscores the need for infection control training and surveillance in these settings.

Disclosures

All Authors: No reported Disclosures.

Abstract P6-18-18: Phase I trial of eribulin and everolimus in patients with metastatic triple negative breast cancer

Background: Alteration of PI3K/Akt/mTOR pathway is the most common genomic abnormality detected in triple negative breast cancer (TNBC). Everolimus acts synergistically with eribulin in inducing apoptosis in TNBC cell lines and xenografts in our preclinical study. This phase I trial was designed to test the safety and tolerability of combining eribulin and everolimus in patients (pts) with metastatic TNBC.

Methods: The overall objective of this study was to describe the safety and toxicities of the combination. The secondary objective was to assess activity based on response rate (RR) and progression free survival (PFS). Eligibility criteria included pts with metastatic TNBC, ECOG 0-2, 0-3 lines of prior chemotherapy in metastatic setting, and prior treatment with anthracycline and/or taxane therapy. The study utilized the toxicity equivalence range (TEQR) design with a target equivalence range for dose-limiting toxicities (DLTs) of 0.20-0.35. The recommended phase 2 dose (RP2D) will be the dose closest to the target of 0.25 below 0.51 based on isotonic regression.Three dosing levels of the combinations were tested: level A1 (everolimus 5mg daily; eribulin 1.4 mg/m2 days 1, 8 every 3 weeks), level A2 (everolimus 7.5mg daily; eribulin 1.4 mg/m2, days 1, 8 every 3 weeks), level B1(everolimus 5mg daily; eribulin 1.1 mg/m2 days 1, 8 every 3 weeks). Nanostring RNA analysis and genomic mutation analysis were conducted in 16 pts with available tumor tissue.

Results: A total of 27 pts were enrolled. Median age was 55 years (range 36-76). Two pts were ineligible due to HER2+ on repeat biopsy and were only included in the toxicity analysis. Dose level B1 (everolimus 5mg daily and eribulin 1.1 mg/m2 days 1, 8 every 3 weeks) was determined to be the RP2D doses. The DLTs were neutropenia, stomatitis and hyperglycemia. Across all cycles, 59% (16/27) had a ≥ Gr3 toxicity attributed to treatment at the possible or above level. 44% (12/27) had Gr3 heme-toxicities. The most common toxicities were ≥ Gr3 neutropenia (10 pts), Gr3 lymphopenia (6 pts) and ≥ Gr3 leukopenia (7 pts). 33% (9/27) had Gr3 non-heme toxicities. The most common were Gr3 stomatitis (3 pts), Gr3 hyperglycemia (3 pts) and Gr3 fatigue (5 pts). The median number of cycles completed was 4 (0-8). 68% (17/25) had a dose modification or hold, 14 of 25 (56%) were for eribulin and 15 of 25 (60%) were for everolimus. Of 25 eligible pts, 8 (32%) achieved a best response as partial response, 11 (44%) had stable disease and 6 (24%) had progression. 80% (20/25) experienced progression by RECIST or showed clinical progression, and the median time to progression was 2.7 mo (95% CI (2.2, 4.6)). At the time of this analysis, 16 participants had died, median OS was 6.3 mo (95% CI (5.3, undefined)). Two pts are still being followed on treatment. PI3K-Akt-mTOR pathway genes and mutations profiles were studied.

Conclusion: Eribulin 1.1 mg/m2 days 1, 8 and everolimus 5mg daily was defined as the RP2D. Genomic analysis is currently underway to understand the molecular mechanisms of resistance.

Citation Format: Yuan Y, Yost S, Blanchard S, Yin H, Li M, Robinson K, Tang A, Martinez N, Leong L, Somlo G, Tank Patel N, Waisman J, Portnow J, Hurria A, Luu T-H, Mortimer J. Phase I trial of eribulin and everolimus in patients with metastatic triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-18.

Contemporary Outcomes and Factors Associated With Mortality After a Fetal or Postnatal Diagnosis of Common Arterial Trunk

BACKGROUND

Common arterial trunk (CAT) is a rare anomaly with a spectrum of pathology. We sought to identify current trends and factors associated with postnatal outcomes.

METHODS

This was a single-centre review including 153 live births with planned surgery. Patients were analyzed as 2 cohorts based on era of CAT diagnosis (1990 to 1999 vs 2000 to 2014) and complexity of disease (simple vs complex). "Complex" required the association with significant aortic arch obstruction, truncal valve (TV) stenosis/regurgitation, and/or branch pulmonary artery (PA) hypoplasia, respectively.

RESULTS

Sixteen (10%) died preoperatively, and this outcome was associated with significant TV stenosis (odds ratio [OR] 4.55; P = 0.01) and regurgitation (OR 3.17; P = 0.04); 130 (95%) of 137 operated infants underwent primary complete repair. Their survival rates to 1 year improved from 54% to 85% after 2000, although this outcome remained substantially lower for cases with a complex vs simple CAT repair (76% vs 95%; OR 6.46; P = 0.006). Other risk factors associated with decreased 1-year survival included diagnosis before 2000 (OR 4.48; P = 0.038) and a lower birth weight (OR 8.0 per kg weight; P = 0.001). Finally, of 93 survivors beyond year 1 of life, 76 (82%) had undergone a total of 224 reinterventions. Only 15 (16%) were alive without any surgical or catheter-based reintervention at study end.

CONCLUSIONS

Despite recent surgical improvements, postnatal mortality continues to be substantial if CAT is complicated by significant pathology of the TV, aortic arch, or branch PAs. Reoperations and catheter interventions are eventualities for most patients during childhood.

Effect of thiourethane filler surface functionalization on stress, conversion and mechanical properties of restorative dental composites

OBJECTIVES

This study evaluated the efficacy of a thiourethane(TU)-modified silane agent in improving properties in filled composites.

METHODS

The TU-silane agent was synthesized by combining 1,3-bis(1-isocyanato-1-methylethyl)benzene and 3-(triethoxysilyl)propyl isocyanate with trimethylol-tris-3-mercaptopropionate (TMP), at 1:2 isocyanate:thiol, leaving pendant thiol and alkoxy silane groups. Barium glass fillers (1μm average particle size) were functionalized with 5wt% TU-silane in an acidic ethanol solution. Commercially available 3-(trimethoxysilyl)propyl methacrylate (MA-silane) and (3-mercaptopropyl)trimethoxysilane (SH-silane), as well as no silane treatment (NO-silane), were used as controls. Composites were made with BisGMA-UDMA-TEGDMA (5:3:2), camphorquinone/ethyl-4-dimethylaminobenzoate (0.2/0.8wt%) and di-tert-butyl hydroxytoluene (0.3wt%) and 70wt% silanated inorganic fillers. Polymerization stress (PS) was measured using a cantilever beam apparatus (Bioman). Methacrylate conversion (DC) and rate of polymerization (RP) during photoactivation (800mW/cm²) were followed in real-time with near-IR. Flexural strength/modulus (FS/FM) were evaluated in three-point bending with 2×2×25 mm.

STATISTICAL ANALYSIS

2-way ANOVA/Tukey's test (α=5%).

RESULTS

DC, Rp_max and E were similar for all groups tested. FS was similar for the TU- and MA-silane, which were statistically higher than the untreated and SH-silane groups. Stress reductions in relation to the MA-silane were observed for all groups, but statistically more markedly for the TU-silane material. This is likely due to stress relaxation and/or toughening provided at the filler interface by the oligomeric TU structure.

SIGNIFICANCE

TU-silane oligomers favorably modified conventional dimethacrylate networks with minimal disruption to existing curing chemistry, in filled composites. For the same conversion values, stress reductions of up to 50% were observed, without compromise to mechanical properties or handling characteristics.

Spermatogenesis-associated 48 is essential for spermatogenesis in mice

Azoospermia, oligospermia and teratozoospermia all seriously impact male reproductive health. Spermatogenesis is a complex and precisely regulated process in which germ cells proliferate and differentiate and involves the regulation of multiple testis-specific genes. Here, we identified testis-specific gene spermatogenesis-associated 48 (SPATA48), the expression of which was age-dependent, indicating that it is involved in spermatogenesis. In humans and mice with azoospermia, expression of SPATA48 disappeared in the testis. Spata48-/- knockout male mice had smaller testis and defective spermatogenesis compared to wild-type (WT) mice. This study can help in the exploration of the genetic basis of male infertility and identify new targets for the diagnosis and treatment of male infertility.

Abstract OT1-05-02: A phase II clinical trial of the combination of pembrolizumab and selective androgen receptor modulator GTx-024 in patients with advanced androgen receptor positive triple negative breast cancer

Background: Androgen receptor (AR) targeted therapy and immunotherapy represent one of the most promising strategies for metastatic triple negative breast cancer (mTNBC), which accounts for 15-20% of all breast cancers. As a nonsteroidal selective androgen receptor modulator (SARM), GTx-024 demonstrated preclinical activity in AR+ TNBC PDX model. Pembrolizumab is a highly selective humanized monoclonal antibody of the programmed cell death 1 receptor (PD-1). The complementary modes of action and low potential for overlapping toxicity make the combination promising in patients with AR+ mTNBC.

Trial Design: This is an open-label Phase 2 study for AR+ mTNBC. Eligible participants receive pembrolizumab 200mg IV every 3 weeks in combination with GTx-024 18mg po daily.

Eligibility Criteria: Eligible patients must have AR+ (&gt;10%, 1+ by IHC) TNBC; failed up to 2 lines of therapy in metastatic setting; and have measurable disease per RECIST1.1. Patients are excluded if they have had prior checkpoint inhibitors or AR targeted agents. Patients with current or prior use of testosterone, testosterone-like agents, androgenic compounds, or anti-androgens (including systemic steroids and immunosuppressive medications)are excluded, as well as current or prior history of noninfectious pneumonitis requiring systemic steroid therapy.

Specific Aims: The primary objective is to evaluate the safety/tolerability of GTx-024 and pembrolizumab and determine the response rate (CR or PR via RECIST 1.1) in patients with advanced AR+ TNBC. We will use clinical benefit rate (CBR), duration of response (DOR), PFS, and OS to test the efficacy of this novel drug combination.

Statistical Design: A Simon's MiniMax two-stage Phase 2 design will be utilized. Based on the previously reported response rate associated with single agent pembrolizumab (19%), we consider a response rate of 19% for the combination as discouraging, and a 39% response rate as encouraging. As a result, we will initially accrue 15 patients (including 6 patients from safety lead-in treated at the tolerable dose). If 2 or fewer patients respond, we will stop accrual for futility. Otherwise, the study will accrue an additional 14 patients for a total of 29 patients. With 29 patients, if only 8 or fewer respond (≤27.6%), the study will be considered discouraging unless secondary evidence of clinical benefit is substantial. With more than 8 patients responding out of the 29 patients, the combination would be considered promising. This design has 85% power to declare a true response rate of 39% as promising (power), and a 10% probability of declaring a true 19% response rate as encouraging (type I error). The probability of early termination if the true response rate is 19% is 44%.

Target Accrual: 29

Study Contact: Yuan Yuan MD PhD, City of Hope Comprehensive Cancer Center; Duarte, CA 91030; Email: yuyuan@coh.org

Citation Format: Yuan Y, Frankel P, Synold T, Lee P, Yost S, Martinez N, Tang A, Mendez B, Schmolze D, Apple S, Hurria A, Waisman J, Somlo G, Tank N, Sedrak M, Mortimer J. A phase II clinical trial of the combination of pembrolizumab and selective androgen receptor modulator GTx-024 in patients with advanced androgen receptor positive triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-05-02.

Predicted global warming scenarios impact on the mother plant to alter seed dormancy and germination behaviour in Arabidopsis

Seed characteristics are key components of plant fitness that are influenced by temperature in their maternal environment, and temperature will change with global warming. To study the effect of such temperature changes, Arabidopsis thaliana plants were grown to produce seeds along a uniquely designed polyethylene tunnel having a thermal gradient reflecting local global warming predictions. Plants therefore experienced the same variations in temperature and light conditions but different mean temperatures. A range of seed-related plant fitness estimates were measured. There were dramatic non-linear temperature effects on the germination behaviour in two contrasting ecotypes. Maternal temperatures lower than 15-16 °C resulted in significantly greater primary dormancy. In addition, the impact of nitrate in the growing media on dormancy was shown only by seeds produced below 15-16 °C. However, there were no consistent effects on seed yield, number, or size. Effects on germination behaviour were shown to be a species characteristic responding to temperature and not time of year. Elevating temperature above this critical value during seed development has the potential to dramatically alter the timing of subsequent seed germination and the proportion entering the soil seed bank. This has potential consequences for the whole plant life cycle and species fitness.