Comparison of imputation methods for missing production data of dairy cattle

Nowadays, vast amounts of data representing feed intake, growth, and environmental impact of individual animals are being recorded in on-farm settings. Despite their apparent use, data collected in real-world applications often have missing values in one or several variables, due to reasons including human error, machine error, or sampling frequency misalignment across multiple variables. Since incomplete datasets are less valuable for downstream data analysis, it is important to address the missing value problem properly. One option may be to reduce the dataset to a subset that contains only complete data, but considerable data may be lost via this process. The current study aimed to compare imputation methods for the estimation of missing values in a raw dataset of dairy cattle including 454 553 records collected from 629 cows between 2009 and 2020. The dataset was subjected to a cleaning process that reduced its size to 437 075 observations corresponding to 512 cows. Missing values were present in four variables: concentrate DM intake (CDMI, missing percentage = 2.30%), forage DM intake (FDMI, 8.05%), milk yield (MY, 15.12%), and BW (64.33%). After removing all missing values, the resulting dataset (n = 129 353) was randomly sampled five times to create five independent subsets that exhibit the same missing data percentages as the cleaned dataset. Four univariate and nine multivariate imputation methods (eight machine learning methods and the MissForest method) were applied and evaluated on the five repeats, and average imputation performance was reported for each repeat. The results showed that Random Forest was overall the best imputation method for this type of data and had a lower mean squared prediction error and higher concordance correlation coefficient than the other imputation methods for all imputed variables. Random Forest performed particularly well for imputing CDMI, MY, and BW, compared to imputing FDMI.

Review: When worlds collide - poultry modeling in the 'Big Data' era

Within poultry production systems, models have provided vital decision support, opportunity analysis, and performance optimization capabilities to nutritionists and producers for decades. In recent years, due to the advancement of digital and sensor technologies, 'Big Data' streams have emerged, optimally positioned to be analyzed by machine-learning (ML) modeling approaches, with strengths in forecasting and prediction. This review explores the evolution of empirical and mechanistic models in poultry production systems, and how these models may interact with new digital tools and technologies. This review will also examine the emergence of ML and Big Data in the poultry production sector, and the emergence of precision feeding and automation of poultry production systems. There are several promising directions for the field, including: (1) application of Big Data analytics (e.g., sensor-based technologies, precision feeding systems) and ML methodologies (e.g., unsupervised and supervised learning algorithms) to feed more precisely to production targets given a 'known' individual animal, and (2) combination and hybridization of data-driven and mechanistic modeling approaches to bridge decision support with improved forecasting capabilities.

Body mass index from the RE-LY trial: further evidence of the obesity paradox

Background

The obesity paradox has been reported in 3 post-hoc analyses evaluating the direct oral anticoagulants (DOAC) against warfarin (W): apixaban (ARISTOTLE), rivaroxaban (ROCKET), and edoxaban (ENGAGE-AF).

Purpose

To evaluate the obesity paradox in a post-hoc analysis of the RE-LY trial, comparing dabigatran 110 mg BID (D110), 150 mg BID (D150), and W by body mass index (BMI).

Methods

Baseline characteristics were evaluated using World Health Organization (WHO) criteria of overweight and obese (BMI ≥25 kg/m2) and under and normal weight (BMI <25 kg/m2). Stroke and systemic embolism, ischemic stroke, major bleeding, mortality, and intracranial hemorrhage were evaluated using BMI as a continuous variable and by the WHO criteria using a cox proportional hazard model.

Results

BMI was available in 99.9% of patients randomized; 74% had a BMI ≥25. At baseline, patients with a BMI ≥25 were younger (70.9 vs 73.1, p<0.001) and had fewer prior strokes (11.5% vs 15.6%, p<0.001), but higher mean creatinine clearance (78.3 vs 57.0, p<0.001) and rates of diabetes (25.8% vs 16.1%, p<0.001) (Table 1). Independent of drug assignment, patients with a BMI ≥25 had lower rates of stroke and systemic embolism (HR 0.65 [95% CI 0.54–0.79], p<0.001), ischemic stroke (0.75 [95% CI 0.60, 0.94], p=0.01), major bleeding (HR 0.79 [95% CI 0.69,0.89], p<0.001), mortality (HR 0.60 [95% CI 0.53, 0.67], p<0.001) and intracranial hemorrhage (HR 0.53 [95% CI 0.38, 0.73], p<0.001) compared to those with a BMI <25. Using BMI as a continuous variable combining all outcomes at 3 years, endpoint rates declined as BMI approached 25 in all 3 treatment groups. The exceptions were intracranial hemorrhage for D110 and D150 and stroke in D150 patients, where rates were low independent of BMI. No significant interaction between BMI and treatment was observed in individual outcomes except for the D110 vs. D150 comparison for major bleeding, in favor of D110 for patients with BMI ≥25 (HR 0.77 [95% CI 0.65, 0.91] and HR 1.12 [95% CI 0.86, 1.47], interaction p=0.0190).

Conclusions

In RE-LY, independent of drug assignment, patients with a higher BMI had improved outcomes, demonstrating the obesity paradox. As BMI increased towards 25, outcome rates improved except for intracranial hemorrhage rates for both D110 and D150 and ischemic stroke rates for D150, which were low independent of BMI. Patients treated with D110 with a BMI ≥25 kg/m2 had significantly lower rates of bleeding compared to D150.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Sharpe Strumia Foundation

Interferon-β Decreases the Hypermetabolic State of Red Blood Cells from Patients with Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory disease characterized by damage to the myelin sheath surrounding axons in the central nervous system. While the exact mechanism of this destruction is unknown, excess nitric oxide (NO) and adenosine triphosphate (ATP) have been measured in tissues and fluids obtained from people with MS. Here, incubation of interferon-beta (IFN-β), an MS drug with an unknown mechanism of action, with red blood cells (RBCs) obtained from people with MS provide evidence of a potential hypermetabolic state in the MS RBC that is decreased with IFN-β intervention. Specifically, binding of all three components of an albumin/C-peptide/Zn²⁺ complex to MS RBCs was significantly increased in comparison to control RBCs. For example, the binding of C-peptide to MS RBCs was significantly increased (3.4 ± 0.1 nM) compared to control RBCs (1.6 ± 0.2 nM). However, C-peptide binding to MS RBCs was reduced to a value (1.6 ± 0.3 nM) statistically equal to that of control RBCs in the presence of 2 nM IFN-β. Similar trends were measured for albumin and Zn²⁺ binding to RBCs when in the presence of IFN-β. RBC function was also affected by incubation of cells with IFN-β. Specifically, RBC-derived ATP and measurable membrane GLUT1 were both significantly decreased (56 and 24%, respectively) in the presence of IFN-β. Collectively, our results suggest that IFN-β inhibits albumin binding to the RBC, thereby reducing its ability to deliver ligands such as C-peptide and Zn²⁺ to the cell and normalizing the basal hypermetabolic state.

ASAS-NANP SYMPOSIUM: MATHEMATICAL MODELING IN ANIMAL NUTRITION: Opportunities and Challenges of Confined and Extensive Precision Livestock Production

Modern animal scientists, industry, and managers have never faced a more complex world. Precision livestock technologies have altered management in confined operations to meet production, environmental, and consumer goals. Applications of precision technologies have been limited in extensive systems such as rangelands due to lack of infrastructure, electrical power, communication, and durability. However, advancements in technology have helped to overcome many of these challenges. Investment in precision technologies is growing within the livestock sector, requiring the need to assess opportunities and challenges associated with implementation to enhance livestock production systems. In this review, precision livestock farming and digital livestock farming are explained in the context of a logical and iterative five-step process to successfully integrate precision livestock measurement and management tools, emphasizing the need for precision system models (PSMs). This five-step process acts as a guide to realize anticipated benefits from precision technologies and avoid unintended consequences. Consequently, the synthesis of precision livestock and modeling examples and key case studies help highlight past challenges and current opportunities within confined and extensive systems. Successfully developing PSM requires appropriate model(s) selection that aligns with desired management goals and precision technology capabilities. Therefore, it is imperative to consider the entire system to ensure that precision technology integration achieves desired goals while remaining economically and managerially sustainable. Achieving long-term success using precision technology requires the next generation of animal scientists to obtain additional skills to keep up with the rapid pace of technology innovation. Building workforce capacity and synergistic relationships between research, industry, and managers will be critical. As the process of precision technology adoption continues in more challenging and harsh, extensive systems, it is likely that confined operations will benefit from required advances in precision technology and PSMs, ultimately strengthening the benefits from precision technology to achieve short- and long-term goals.

Systemic IL-15 promotes allogeneic cell rejection in patients treated with natural killer cell adoptive therapy

Natural killer (NK) cells are a promising alternative to T cells for cancer immunotherapy. Adoptive therapies with allogeneic, cytokine-activated NK cells are being investigated in clinical trials. However, the optimal cytokine support after adoptive transfer to promote NK cell expansion, and persistence remains unclear. Correlative studies from 2 independent clinical trial cohorts treated with major histocompatibility complex-haploidentical NK cell therapy for relapsed/refractory acute myeloid leukemia revealed that cytokine support by systemic interleukin-15 (IL-15; N-803) resulted in reduced clinical activity, compared with IL-2. We hypothesized that the mechanism responsible was IL-15/N-803 promoting recipient CD8 T-cell activation that in turn accelerated donor NK cell rejection. This idea was supported by increased proliferating CD8+ T-cell numbers in patients treated with IL-15/N-803, compared with IL-2. Moreover, mixed lymphocyte reactions showed that IL-15/N-803 enhanced responder CD8 T-cell activation and proliferation, compared with IL-2 alone. Additionally, IL-15/N-803 accelerated the ability of responding T cells to kill stimulator-derived memory-like NK cells, demonstrating that additional IL-15 can hasten donor NK cell elimination. Thus, systemic IL-15 used to support allogeneic cell therapy may paradoxically limit their therapeutic window of opportunity and clinical activity. This study indicates that stimulating patient CD8 T-cell allo-rejection responses may critically limit allogeneic cellular therapy supported with IL-15. This trial was registered at www.clinicaltrials.gov as #NCT03050216 and #NCT01898793.

358 Ramucirumab in combination with pembrolizumab as first-line treatment for recurrent or metastatic head and neck squamous-cell carcinoma: a phase 1–2 trial

Background

VEGF, a key mediator of angiogenesis and resistance to immunotherapy, is overexpressed in head and neck squamous-cell carcinoma (HNSCC). The primary aims of this trial were to determine the recommended phase 2 dose (RP2D) of ramucirumab, a potent inhibitor of VEGF receptor-2, given with pembrolizumab, and the objective response rate (ORR) of this combination as first-line treatment for recurrent or metastatic (RM)-HNSCC.

Methods

Study participants provided written informed consent. Eligible patients had incurable HNSCC originating in the oral cavity, oropharynx, larynx, or hypopharynx. RM disease within 6 months of curative-intent systemic therapy and programmed death ligand (PD-L1) negative disease were permitted. In a dose de-escalation phase 1 design, patients received ramucirumab (level one: 10 mg/kg; then 8 and 6 mg/kg) and pembrolizumab (200 mg) on day 1 of each 21-day cycle until discontinuation criteria were met. Each dose level included three patients. The RP2D of ramucirumab was defined as the highest dose level at which one or fewer patients experienced a dose-limiting toxicity (DLT) during cycle one. In a Simon two-stage phase 2 design, patients with measurable, previously untreated RM-HNSCC received ramucirumab at the RP2D with pembrolizumab. Tumor response was assessed by RECIST1.1. When the trial was developed, the ORR of pembrolizumab given as first-line treatment wasn’t known; however, the ORR for platinum pre-treated disease was 13–18%. Therefore, an ORR of <13% was deemed unacceptable and an ORR of >32% was of clinical interest. In stage one, two or more responses among ten patients were required to enroll to stage two. Eight or more responses among 33 evaluable patients (those with at least one response assessment) was evidence for efficacy (80% power; one-sided α= 0.05).

Results

Three patients were treated in phase 1 and 37 in phase 2. Eleven patients (28%) had recurrent disease within 6 months of curative-intent systemic therapy. In phase 1, no DLT occurred at the starting dose of ramucirumab. Tumor response occurred in 2 of these 3 patients. In phase 2, tumor response occurred in 19 of 33 evaluable patients (ORR 57.6%, 95%CI: 39.2–74.5). Tumor response by PD-L1 CPS is shown in the table below (table 1). No unexpected safety concerns were identified.

Abstract 358 Table 1

Conclusions

The RP2D of ramucirumab given with pembrolizumab was 10 mg/kg on day 1 of each 21-day cycle. The primary hypothesis was accepted: the ORR with ramucirumab and pembrolizumab was higher than expected with pembrolizumab monotherapy when given as first-line treatment for RM-HNSCC.

Trial Registration

This trial is registered with ClinicalTrials.gov (NCT03650764).

Ethics Approval

This study was approved by Washington University’s Ethics Board; approval number 201809094.

Memory-like Differentiation Enhances NK Cell Responses to Melanoma

PURPOSE

Treatment of advanced melanoma is a clinical challenge. Natural killer (NK) cells are a promising cellular therapy for T cell-refractory cancers, but are frequently deficient or dysfunctional in patients with melanoma. Thus, new strategies are needed to enhance NK-cell antitumor responses. Cytokine-induced memory-like (ML) differentiation overcomes many barriers in the NK-cell therapeutics field, resulting in potent cytotoxicity and enhanced cytokine production against blood cancer targets. However, the preclinical activity of ML NK against solid tumors remains largely undefined.

EXPERIMENTAL DESIGN

Phenotypic and functional alterations of blood and advanced melanoma infiltrating NK cells were evaluated using mass cytometry. ML NK cells from healthy donors (HD) and patients with advanced melanoma were evaluated for their ability to produce IFNγ and kill melanoma targets in vitro and in vivo using a xenograft model.

RESULTS

NK cells in advanced melanoma exhibited a decreased cytotoxic potential compared with blood NK cells. ML NK cells differentiated from HD and patients with advanced melanoma displayed enhanced IFNγ production and cytotoxicity against melanoma targets. This included ML differentiation enhancing melanoma patients' NK-cell responses against autologous targets. The ML NK-cell response against melanoma was partially dependent on the NKG2D- and NKp46-activating receptors. Furthermore, in xenograft NSG mouse models, human ML NK cells demonstrated superior control of melanoma, compared with conventional NK cells.

CONCLUSIONS

Blood NK cells from allogeneic HD or patients with advanced melanoma can be differentiated into ML NK cells for use as a novel immunotherapeutic treatment for advanced melanoma, which warrants testing in early-phase clinical trials.

Outcome of older hip fracture patients on anticoagulation: a comparison of vitamin K-antagonists and Factor Xa inhibitors

INTRODUCTION

Older hip fracture patients are still challenging in daily clinical practice. Due to the high prevalence of osteoporosis and atrial fibrillation in this age group, the number of fragility fracture patients under oral anticoagulation (OAC) increases. The outcome is still disappointing, short- and long-term mortality and morbidity is high. The impact of pre-existing OAC is not yet clear, especially regarding new OAC drugs like Factor Xa inhibitors (FXa). The purpose of our study was to compare the short-term outcome of older hip fracture patients, without OAC (controls), on Vitamin K antagonists (VKA) and on FXa.

MATERIALS AND METHODS

The study is a retrospective case-control study including patients older than 70 years who sustained hip fractures caused by an inadequate trauma and treated at a level 1 trauma center from February 2017 to June 2018. Patient's information was taken from patient's charts. 102 cases were analysed, 61 controls, 41 on OAC (15 on VKA and 26 on FXa). As outcome parameter we defined mortality, perioperative complications, bleeding, need of blood supplements, delay of surgery, length of stay, and a combined outcome parameter (mortality, myocardial infarction, stroke, thromboembolic events, blood preservations, re-vision surgery, major bleeding and decline of hemoglobin).

RESULTS

Eight patients died during hospital stay, in-hospital mortality was 7.8%. The highest mortality rate was found in patients on VKA (20%), compared to patients on FXa (3.8%) and controls (6.6%). However, mortality rate did not differ significantly within the groups. The combined endpoint was significantly more frequently seen in patients on OAC compared to controls (p = 0.006). No difference was observed between patients on VKA or FXa. Mean time to surgery and LOS was significantly longer in patients on OAC compared to controls. No significant differences were seen between VKA and FXa.

CONCLUSIONS

In our study OAC was significantly associated with worse outcome compared to controls. Marginal differences were observed between patients on FXa or VKA. Further studies involving a higher number of patients are necessary to confirm our results. At that time, some our results have to interpreted carefully and need confirmation.

SAT0422 FIRST-LINE CSDMARD MONOTHERAPY RETENTION IN PSORIATIC ARTHRITIS: METHOTREXATE OUTPERFORMS SULFASALAZINE

Background:

Conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) are the first-line treatment for psoriatic arthritis (PsA), but there is conflicting data regarding their efficacy and scarce reports describing the duration of use (drug retention) of csDMARD in this population. Their position in treatment recommendations is a matter of growing debate due the availability of alternative treatment options with higher levels of evidence.

Objectives:

To study drug retention and predictors for drug retention among PsA patients receiving first-line csDMARD monotherapy.

Methods:

Retrospective cohort study in DMARD-naïve adult PsA patients in whom a first csDMARD was prescribed as monotherapy primarily to treat PsA-related symptoms. Main outcome was time to failure of the csDMARD (i.e stopping the csDMARD or adding another DMARD).

Results:

187 patients were included, who were mainly prescribed methotrexate (MTX) (n=163) or sulfasalazine (SSZ) (n=21) (Table 1). The pooled median time to failure was 31.8 months (IQR 9.04-110). Drug retention was significantly higher in MTX (median 34.5 months; IQR 9.60-123) as compared to SSZ treated patients (median 12.0 months; IQR 4.80-55.7)(p=0.016, log-rank test) (Figure 1). In multivariable cox-regression the use of MTX and older age were associated with increased retention. The main reasons for treatment failure were inefficacy (52%) and side-effects (28%) (Figure 2). Upon failure, MTX treated patients were more commonly, subsequently treated with a biologic DMARD compared to SSZ (p<0.05).

Table 1.

Main demographic and clinical characteristics of the study population at baseline. The total cohort (n=187) included 3 patients treated with leflunomide (data not shown separately). Psoriasis area and severity scores were unavailable for most cases and not shown. Descriptive data show the mean ± SD, median (IQR) or N (%).

Total, N = 187MTX, N = 163SSZ, N = 21Male, N (%)128 (31.6)115 (71)12 (57) Age (years), mean ± SD*48.3 ± 13.349.1 ± 12.739.5 ± 13.4 Body mass index, mean ± SD*26.7 ± 4.527.4 ± 4.425.3 ± 3.5 Smoker, N (%)34/150 (18.2)31/129 (19.0)3/18 (14.3)Disease duration (years), median (IQR) PsA0.4 (0.1 – 3.0)0.4 (0.1 – 2.9)0.3 (0.1 – 2.0) Psoriasis7.5 (2.1 – 18.4)7.5 (2.0 – 15.7)10.8 (3.1 – 26.7)Psoriasis phenotype, N (%)* Vulgaris only130/185 (69.5)117/161 (71.8)10/21 (47.6) Sine psoriasis31/185 (16.6)21/161 (12.9)10/21 (47.6) Other types124/185 (12.8)23/161 (14.1)1/21 (4.8)Nail disease present, N (%)81/121 (43.3)72/104 (44.2)9/17 (42.9)Swollen joint count, median (IQR)*4 (2 – 6)4 (2 – 6)2 (1 – 3)Tender joint count, median (IQR)*4 (1 – 6)4 (2 – 6)1 (0 – 3)Dactylitis present, N (%)18/161 (9.6)17/142 (10.4)1/17 (4.8)Axial disease present2, N (%)27/185 (14.4)24/161 (14.7)3/21 (14.3)CRP, median (IQR)8.0 (2.9 – 16.0)8.0 (3.0 – 15.0)10.0 (1.0 – 26.0)ESR, median (IQR)14.0 (6.0 – 27.5)14.0 (7.0 – 27.0)16.0 (6.0 – 31.0)Erosive disease, N (%)40/156 (21.4)37/140 (22.7)2/15 (9.5)

1Other psoriasis types included guttate, palmoplantaris, inverse, and mixed types.

2Presence/absence of axial disease was based on the clinical diagnosis from the treating physician.

* Clinical parameter is significantly different (P <0.05) between MTX and SSZ.

Abbreviations: MTX = methotrexate. SSZ = sulfasalazine. CRP = C-reactive protein. ESR = erythrocyte sedimentation rate. PsA = psoriatic arthritis.

Conclusion:

MTX outperformed SSZ as first-line csDMARD monotherapy in DMARD-naïve PsA patients with respect to drug retention in daily clinical practice.

References:

n.a.

Disclosure of Interests:

Marleen Jacobs: None declared, Juliette Pouw: None declared, Paco Welsing: None declared, Timothy RDJ Radstake Employee of: TR currently is an employee of AbbVie. At the time of the work described he had no COIs., Emmerik Leijten: None declared

The GOLIATH Project: Towards an Internationally Harmonised Approach for Testing Metabolism Disrupting Compounds

The purpose of this project report is to introduce the European "GOLIATH" project, a new research project which addresses one of the most urgent regulatory needs in the testing of endocrine-disrupting chemicals (EDCs), namely the lack of methods for testing EDCs that disrupt metabolism and metabolic functions. These chemicals collectively referred to as "metabolism disrupting compounds" (MDCs) are natural and anthropogenic chemicals that can promote metabolic changes that can ultimately result in obesity, diabetes, and/or fatty liver in humans. This project report introduces the main approaches of the project and provides a focused review of the evidence of metabolic disruption for selected EDCs. GOLIATH will generate the world's first integrated approach to testing and assessment (IATA) specifically tailored to MDCs. GOLIATH will focus on the main cellular targets of metabolic disruption-hepatocytes, pancreatic endocrine cells, myocytes and adipocytes-and using an adverse outcome pathway (AOP) framework will provide key information on MDC-related mode of action by incorporating multi-omic analyses and translating results from in silico, in vitro, and in vivo models and assays to adverse metabolic health outcomes in humans at real-life exposures. Given the importance of international acceptance of the developed test methods for regulatory use, GOLIATH will link with ongoing initiatives of the Organisation for Economic Development (OECD) for test method (pre-)validation, IATA, and AOP development.

The Y-chromosome F haplogroup contributes to the development of Barrett's esophagus-associated esophageal adenocarcinoma in a white male population

Barrett's esophagus (BE) is a metaplastic condition of the distal esophagus, resulting from longstanding gastroesophageal reflux disease (GERD). BE predisposes for the highly malignant esophageal adenocarcinoma (EAC). Both BE and EAC have the highest frequencies in white males. Only a subset of patients with GERD develop BE, while <0.5% of BE will progress to EAC. Therefore, it is most likely that the development of BE and EAC is associated with underlying genetic factors. We hypothesized that in white males, Y-chromosomal haplogroups are associated with BE and EAC. To investigate this we conducted a multicenter study studying the frequencies of the Y-chromosomal haplogroups in GERD, BE, and EAC patients. We used genomic analysis by polymerase chain reaction and restriction fragment length polymorphism to determine the frequency of six Y-chromosomal haplogroups (DE, F(xJ,xK), K(xP), J, P(xR1a), and R1a) between GERD, BE, and EAC in a cohort of 1,365 white males, including 612 GERD, 753 BE patients, while 178 of the BE patients also had BE-associated EAC. Univariate logistic regression analysis was used to compare the outcomes. In this study, we found the R1a (6% vs. 9%, P = 0.04) and K (3% vs. 6%, P = 0.035) to be significantly underrepresented in BE patients as compared to GERD patients with an odds ratio (OR) of 0.63 (95% CI 0.42-0.95, P = 0.03) and of 0.56 (95% CI 0.33-0.96, P = 0.03), respectively, while the K haplogroup was protective against EAC (OR 0.30; 95% CI 0.07-0.86, P = 0.05). A significant overrepresentation of the F haplogroup was found in EAC compared to BE and GERD patients (34% vs. 27% and 23%, respectively). The F haplogroup was found to be a risk factor for EAC with an OR of 1.5 (95% CI 1.03-2.19, P = 0.03). We identified the R1a and K haplogroups as protective factors against development of BE. These haplogroups have low frequencies in white male populations. Of importance is that we could link the presence of the predominantly occurring F haplogroup in white males to EAC. It is possible that this F haplogroup is associated to genetic variants that predispose for the EAC development. In future, the haplogroups could be applied to improve stratification of BE and GERD patients with increased risk to develop BE and/or EAC.

P3599Minicare high sensitivity troponin: a novel point-of-care tool to improve ACS workflows

Background

Cardiac troponin (cTn) has been broadly accepted as the biomarker of choice in the diagnosis of patients presenting with Acute Coronary Syndrome (ACS). Point-of-care (POC) cTn testing, defined as testing near the patient with rapid availability of results, has attracted a strong interest in the emergency department (ED) setting. It offers the potential to improve workflows, expedite clinical decisions and to reduce the length of stay. Workflows could be further optimized when a first measurement can already be performed by the emergency medical services prior to admission to the hospital.

Advances in assay technology have led to high sensitive (HS) cTn assays that have a profound impact on clinical practice, providing early results at presentation and 1 hour after admission which speed up clinical decision-making. Here we evaluate the Minicare HS cTnI POC test under development, which has the potential to combine the benefits of HS-cTnI protocols with a POC workflow.

Objective

Evaluate the analytical and clinical capability of the Minicare HS-cTnI test under development to meet the criteria‡ for HS cTn of having a 10% CV <99th percentile and a percentage measurable (>LoD) of >50%.

Methods

The evaluation is based on the Clinical Laboratory Standards Institute (CLSI) guidelines. Li-heparin whole blood and Li-heparin plasma samples were used to establish LoB, LoD, and LoQ, sample matrix comparison and linearity in the low range. The clinical performance for Minicare HS-cTnI was assessed and compared to Abbott Architect high-sensitivity troponin using banked samples from patients with ACS and collected at t=2–4h after admission. The percentage measurable was assessed and compared to Abbott Architect high-sensitivity troponin in a healthy population of 165 individuals.

Results

With a time to result within 10 minutes, the LoB is determined at 1.0 ng/L and the LoD at 2.1 ng/L. Plasma and whole blood results correlated well and showed comparable results. The 10% and 20% CV LoQ are established at 7.9 ng/L and 3.1 ng/L, well below the anticipated 99th percentile of 26 ng/L. With a percentage measurable of 77%, the criteria for a HS-cTnI assay are met in a POC device. A sensitivity of 93% and an NPV of 99% are found for Minicare HS-cTnI for a t=2–4h protocol vs 90% and 98% for Abbott Architect high-sensitivity troponin. In this study the area under the curve is 0.98 for Minicare HS-cTnI and 0.97 for Architect HS-cTnI.

ROC curve t=2-4 h

Conclusions

With HS-cTnI capability on the Minicare platform, we show the potential to support a 0/1 h sampling protocol, combined with the speed of a POC workflow. This may enable even more rapid and safe rule-out of patients with ACS.

1202The incidence, treatment and mortality of new-onset atrial fibrillation patients at the intensive care unit

Background

Critically ill patients admitted to the intensive care unit (ICU) often develop atrial fibrillation (AF), with an incidence of around 5%. Stroke prevention in AF is well described in clinical guidelines. However, the extent to which stroke prevention is prescribed to ICU patients with AF is unknown.

Purpose

We aimed to determine the incidence of new-onset AF and describe the stroke prevention strategies that were initiated on the ICU of our teaching hospital. Also, we compared mortality in patients with new-onset AF to critically ill patients with previously diagnosed AF and patients without any AF.

Methods

This study was a retrospective cohort study including all admissions to the ICU of the our hospital in the period 2011–2016. Propensity score matching was used to compare the different patient groups. Survival analyses were performed using these real-world data.

Results

In total, 3334 patients were admitted to the ICU, of whom 213 patients (6.4%) developed new-onset AF. 583 patients (17.5%) had a previous diagnosis of AF, the other patients (76.1%) were in normal sinus rhythm. In-hospital mortality and one-year mortality after hospital discharge were significantly higher for new-onset AF patients compared to patients with no history of AF or previously diagnosed AF. At hospital discharge, only 50.4% of the new-onset AF-patients eligible for stroke prevention received an anticoagulant and anticoagulation was not dependent on CHA2DS2VASc score or other patient characteristics. An effect of anticoagulative status on mortality was not significant.

Conclusion

AF is associated with increased mortality in critically ill patients that were admitted to the ICU. More guidance is needed to optimize anticoagulant treatment in critically ill new-onset AF patients.

Acknowledgement/Funding

None

Abstract P4-06-02: Germline analysis of breast cancer patients with abnormal somatic results: Ancillary assessment or critical co-diagnostic?

Background: Tumor genetic testing (TGT) is increasingly used for planning cancer treatment and identifying appropriate clinical trials. Emerging literature shows that 4–12% of genetic variants identified on TGT are also present in the germline, conferring hereditary cancer risk. Germline genetic testing (GGT) guidelines were recently expanded to include the identification of a BRCA1/BRCA2 variant on TGT as an indication for germline analysis. We evaluated the diagnostic yield of current GGT guidelines by assessing the rate of pathogenic and likely pathogenic (P/LP) germline findings in a series of patients who had a variant identified on TGT and underwent GGT. Methods: We analyzed de-identified data from 185 sequential patients with various tumor types who had TGT and GGT. Personal and family histories were compared to all available NCCN guidelines for GGT. Results: Sixty-four of 185 patients (34.6%) had at least one P/LP germline variant, and among these patients, 42% (27/64) had variants in BRCA1/BRCA2. Variants in all but one patient (26/27) were also found on TGT. Fourteen of 27 (52%) patients had a personal diagnosis of cancer not typically associated with BRCA1/BRCA2, including colorectal (5), lung (3), and one each of cervical, cholangiocarcinoma, gastric, thymus, thyroid, and uterine. Furthermore, prior TGT results were the only reason GGT guidelines were met in 12 of 27 (44%) patients with germline BRCA1/BRCA2 variants. Among 34 patients with a personal history of breast or ovarian cancer, a P/LP germline variant was identified in nine (26%); the majority (5 of 9) were in non-BRCA1/BRCA2 genes including CDKN2A (1), FANCA (1), MUTYH (1), and PALB2 (2). Notably, the patient with the CDKN2A variant did not meet current breast cancer guidelines for GGT, and one patient with breast cancer and a germline BRCA2 mutation only met GGT guidelines due to prior TGT results. Discussion: Genetic testing guidelines have begun to reflect the opportunity for TGT to identify families at risk for hereditary cancer. Expanding GGT criteria to include TGT results is critical for capturing patients who may not otherwise receive GGT. Our data showed a substantial diagnostic yield in patients—including those with breast or ovarian cancer—who completed GGT after variant identification on TGT. Although current genetic testing guidelines capture the portion of these patients with a BRCA1/BRCA2 mutation identified with TGT, our data suggest that P/LP variants in other genes should also be considered during the evaluation of TGT results for subsequent GTG. Finally, the broad spectrum of tumor types with BRCA1/BRCA2 P/LP variants emphasizes the need for all clinicians, regardless of subspecialty, to be aware of current GTG recommendations when TGT identifies a BRCA1/BRCA2 variant and the potential implications of GTG, including targeted therapy, screening, prevention, and family testing.

Citation Format: Blanco AM, Yang S, Michalski ST, Ouyang K, Hamlington B, Fulbright J, Erhard K, Kang HC, Jacobs M, Koptiuch C, Vig H, Silver E, Benson C, Massingham L, Lincoln SE, Nussbaum RL, Hampel H, Esplin ED. Germline analysis of breast cancer patients with abnormal somatic results: Ancillary assessment or critical co-diagnostic? [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 P4-06-02.

Minimal modulation of the host immune response to SIS matrix implants by mesenchymal stem cells from the amniotic fluid

PURPOSE

Surgical restoration of soft tissue defects often requires implantable devices. The clinical outcome of the surgery is determined by the properties inherent to the used matrix. Mesenchymal stem cells (MSC) modulate the immune processes after in vivo transplantation and their addition to matrices is associated with constructive remodeling. Herein we evaluate the potential of MSC derived from the amniotic fluid (AF-MSC), an interesting MSC source for cell therapeutic applications in the perinatal period, for immune modulation when added to a biomaterial.

METHODS

We implant cell free small intestinal submucosa (SIS) or SIS seeded with AF-MSC at a density of 1 × 10⁵/cm² subcutaneously at the abdominal wall in immune competent rats. The host immune response is evaluated at 3, 7 and 14 days postoperatively.

RESULTS

The matrix-specific or cellular characteristics are not altered after 24 h of in vitro co-culture of SIS with AF-MSC. The host immune response was not different between animals implanted with cell free or AF-MSC-seeded SIS in terms of cellular infiltration, vascularity, macrophage polarization or scaffold replacement. Profiling the mRNA expression level of inflammatory cytokines at the matrix interface shows a significant reduction in the expression of the pro-inflammatory marker Tnf-α and a trend towards lower iNos expression upon AF-MSC-seeding of the SIS matrix. Anti-inflammatory marker expression does not alter upon cell seeding of matrix implants.

CONCLUSION

We conclude that SIS is a suitable substrate for in vitro culture of AF-MSC and fibroblasts. AF-MSC addition to SIS does not significantly modulate the host immune response after subcutaneous implantation in rats.

Openspritzer: an open hardware pressure ejection system for reliably delivering picolitre volumes

The ability to reliably and precisely deliver picolitre volumes is an important component of biological research. Here we describe a high-performance, low-cost, open hardware pressure ejection system (Openspritzer), which can be constructed from off the shelf components. The device is capable of delivering minute doses of reagents to a wide range of biological and chemical systems. In this work, we characterise the performance of the device and compare it to a popular commercial system using two-photon fluorescence microscopy. We found that Openspritzer provides the same level of control over delivered reagent dose as the commercial system. Next, we demonstrate the utility of Openspritzer in a series of standard neurobiological applications. First, we used Openspritzer to deliver precise amounts of reagents to hippocampal neurons to elicit time- and dose-precise responses on neuronal voltage. Second, we used Openspritzer to deliver infectious viral and bacterial agents to living tissue. This included viral transfection of hippocampal interneurons with channelrhodopsin for the optogenetic manipulation of hippocampal circuitry with light. We anticipate that due to its high performance and low cost Openspritzer will be of interest to a broad range of researchers working in the life and physical sciences.

Surgical sutures: coincidence or experience?

BACKGROUND

Knotting sutures by hand is still important in daily surgical routine, especially laparotomy closure. The expectation is that hand suturing relies on the experience and subjective estimation of the surgeon. The aim of this study was to investigate whether hand suturing tension is reproducible and if surgical experience influences reproducibility.

METHODS

At the annual Congress of the German Association of Surgery, 118 surgeons performed repetitive sutures on a standardized and certified measuring device simulating the final knot of a fascial closure. Each surgeon was asked to perform five identical single knots in a row using the suture tension that each considered ideal. Tension during knotting was measured in Newtons. The surgeons were divided into five subgroups based on surgical experience: group 1, <1 year; group 2, 2-5 years; group 3, 6-10 years; group 4, 11-20 years; and group 5, >30 years.

RESULTS

The tension measured at the end of knotting ranged from 0.19 to 10 N. The mean suture tension at endpoint was 3.88 N for group 1 and slightly higher in the other groups, but not significantly different. The overall mean suture tension was 5.43 N and did not correlate with surgical experience. Suture tension was not reproducible.

CONCLUSION

Sequential suture tension varied, even among experienced surgeons. The ideal tissue-dependent suture tension has not been defined. Measured values appear to be intuitive, relying on individual feeling rather than the level of experience.

[Driving with Alzheimer's disease]

OBJECTIVE

To summarise the available literature on driving with Alzheimer's disease (AD) and to investigate the relationship between driving and cognitive functioning.

DESIGN

Literature review.

METHOD

A systematic search of the electronic databases PubMed/MEDLINE was conducted to select the relevant literature on the driving competence of patients with Alzheimer's disease.

RESULTS

A total of 31 studies were selected that investigated driving competence in AD using either an on-road driving assessment or a driving simulator. The driving competence of patients with AD was less accurate compared with controls. The most commonly made errors included errors in staying in lane, lane changing, slower reaction times, and more fluctuations in speed. Cognitive functioning was more predictive of driving competence than a diagnosis of AD alone.

CONCLUSION

Based on the available literature it is difficult to determine when patients with AD should be restricted in their driving. In addition, there is currently no consensus on which neuropsychological tests are useful in clinical practice to predict driving competence. Specific practical guidelines that can be implemented in daily practice are still lacking.

Development and feasibility of a web-based question prompt sheet to support information provision of health-related quality of life topics after oesophageal cancer surgery

We developed a web-based question prompt sheet (QPS) to support information provision of health-related quality of life (HRQL) topics after oesophageal cancer surgery. The QPS was evaluated and updated in three consecutive studies. In Study 1, eight patients were guided in using the QPS. Feasibility was assessed by cognitive walkthrough, questionnaire and interview. We obtained 430 notes (217 negative, 213 positive) of patients' actions and or remarks, and 91 suggestions. With minor support, most patients were able to use the QPS. In Study 2, forty patients independently used and appraised a modified version of the QPS by questionnaire. All patients deemed the QPS to be usable and useful. In Study 3, 21 patients and three surgeons used the QPS in clinical practice. Clinical feasibility was assessed by the number of QPS sent to the researcher/surgeon. Patients and surgeons were surveyed and the follow-up consultation was audio-recorded. Surgeons were additionally interviewed. Twenty/fourteen patients sent their QPS to the researcher/surgeon. Five QPSs were read by the consultation surgeon. Patients considered the QPS usable and useful. Surgeons considered the QPS of added value and helpful in informing patients, but currently not clinically feasible due to increased consultation time.

Scientific principles for the identification of endocrine-disrupting chemicals: a consensus statement

Endocrine disruption is a specific form of toxicity, where natural and/or anthropogenic chemicals, known as "endocrine disruptors" (EDs), trigger adverse health effects by disrupting the endogenous hormone system. There is need to harmonize guidance on the regulation of EDs, but this has been hampered by what appeared as a lack of consensus among scientists. This publication provides summary information about a consensus reached by a group of world-leading scientists that can serve as the basis for the development of ED criteria in relevant EU legislation. Twenty-three international scientists from different disciplines discussed principles and open questions on ED identification as outlined in a draft consensus paper at an expert meeting hosted by the German Federal Institute for Risk Assessment (BfR) in Berlin, Germany on 11-12 April 2016. Participants reached a consensus regarding scientific principles for the identification of EDs. The paper discusses the consensus reached on background, definition of an ED and related concepts, sources of uncertainty, scientific principles important for ED identification, and research needs. It highlights the difficulty in retrospectively reconstructing ED exposure, insufficient range of validated test systems for EDs, and some issues impacting on the evaluation of the risk from EDs, such as non-monotonic dose-response and thresholds, modes of action, and exposure assessment. This report provides the consensus statement on EDs agreed among all participating scientists. The meeting facilitated a productive debate and reduced a number of differences in views. It is expected that the consensus reached will serve as an important basis for the development of regulatory ED criteria.

Global minimally invasive pyeloplasty study in children: Results from the Pediatric Urology Expert Group of the European Association of Urology Young Academic Urologists working party

INTRODUCTION

Minimally invasive pyeloplasty (MIP) for ureteropelvic junction (UPJ) obstruction in children has gained popularity over the past decade as an alternative to open surgery. The present study aimed to identify the factors affecting complication rates of MIP in children, and to compare the outcomes of laparoscopic (LP) and robotic-assisted laparoscopic pyeloplasty (RALP).

MATERIALS AND METHODS

The perioperative data of 783 pediatric patients (<18 years old) from 15 academic centers who underwent either LP or RALP with an Anderson Hynes dismembered pyeloplasty technique were retrospectively evaluated. Redo cases and patients with anatomic renal abnormalities were excluded. Demographics and operative data, including procedural factors, were collected. Complications were classified according to the Satava and modified Clavien systems. Failure was defined as any of the following: obstructive parameters on diuretic renal scintigraphy, decline in renal function, progressive hydronephrosis, or symptom relapse. Univariate and multivariate analysis were applied to identify factors affecting the complication rates. All parameters were compared between LP and RALP.

RESULTS

A total of 575 children met the inclusion criteria. Laparoscopy, increased operative time, prolonged hospital stay, ureteral stenting technique, and time required for stenting were factors influencing complication rates on univariate analysis. None of those factors remained significant on multivariate analysis. Mean follow-up was 12.8 ± 9.8 months for RALP and 45.2 ± 33.8 months for LP (P = 0.001). Hospital stay and time for stenting were shorter for robotic pyeloplasty (P < 0.05 for both). Success rates were similar between RALP and LP (99.5% vs 97.3%, P = 0.11). The intraoperative complication rate was comparable between RALP and LP (3.8% vs 7.4%, P = 0.06). However, the postoperative complication rate was significantly higher in the LP group (3.2% for RALP and 7.7% for LP, P = 0.02). All complications were of no greater severity than Satava Grade IIa and Clavien Grade IIIb.

DISCUSSION

This was the largest multicenter series of LP and RALP in the pediatric population. Limitations of the study included the retrospective design and lack of surgical experience as a confounder.

CONCLUSIONS

Both minimally invasive approaches that were studied were safe and highly effective in treating UPJ obstruction in children in many centers globally. However, shorter hospitalization time and lower postoperative complication rates with RALP were noted. The aims of the study were met.

Progression of motor subtypes in Huntington's disease: a 6-year follow-up study

The objective of this study is to investigate the progression of predominantly choreatic and hypokinetic-rigid signs in Huntington’s disease (HD) and their relationship with cognitive and general functioning over time. The motor signs in HD can be divided into predominantly choreatic and hypokinetic-rigid subtypes. It has been reported in cross-sectional studies that predominantly choreatic HD patients perform better on functional and cognitive assessments compared to predominantly hypokinetic-rigid HD patients. The course of these motor subtypes and their clinical profiles has not been investigated longitudinally. A total of 4135 subjects who participated in the European HD Network REGISTRY study were included and classified at baseline as either predominantly choreatic (n = 891), hypokinetic-rigid (n = 916), or mixed-motor (n = 2328), based on a previously used method. The maximum follow-up period was 6 years. The mixed-motor group was not included in the analyses. Linear mixed models were constructed to investigate changes in motor subtypes over time and their relationship with cognitive and functional decline. Over the 6-year follow-up period, the predominantly choreatic group showed a significant decrease in chorea, while hypokinetic-rigid symptoms slightly increased in the hypokinetic-rigid group. On the Total Functional Capacity, Stroop test, and Verbal fluency task the rate of change over time was significantly faster in the predominantly choreatic group, while on all other clinical assessments the decline was comparable for both groups. Our results suggest that choreatic symptoms decrease over time, whereas hypokinetic-rigid symptoms slightly increase in a large cohort of HD patients. Moreover, different motor subtypes can be related to different clinical profiles.

Patients with oesophageal cancer report elevated distress and problems yet do not have an explicit wish for referral prior to receiving their medical treatment plan

OBJECTIVE

This study aims to identify patients with oesophageal cancer's level of distress, type of problems, and wish for referral prior to treatment. To identify the clinical relevance of patients with oesophageal cancer's level of distress and type of problems, we build models to predict elevated distress, wish for referral, and overall survival.

METHODS

We implemented the Distress Thermometer and Problem List in daily clinical practice. A score of ≥5 on the Distress Thermometer reflected elevated distress. We first created an initial model including predictors based on the literature. We then added predictors to the initial model to create an extended model based on the sample data. We used the 'least absolute shrinkage and selection operator' to define our final model.

RESULTS

We obtained data from 187 patients (47.9%, of 390 eligible patients with oesophageal cancer) which were similar to non-respondents in their demographic and clinical characteristics. One-hundred thirteen (60%) patients reported elevated distress. The five most frequently reported problems were as follows: eating, tension, weight change, fatigue, and pain. Most patients did not have a wish for referral. Predictors for elevated distress were as follows: being female, total number of practical, emotional, and physical problems, pain, and fatigue. For referral, we identified age, the total number of emotional problems, the level of distress, and fear. The level of distress added prognostic information in a model to predict overall survival.

CONCLUSIONS

Patients with oesophageal cancer report elevated distress and a myriad of problems yet do not have an explicit wish for referral prior to receiving their medical treatment plan. Copyright © 2016 John Wiley & Sons, Ltd.

Binding of the substrate UDP-glucuronic acid induces conformational changes in the xanthan gum glucuronosyltransferase

GumK is a membrane-associated glucuronosyltransferase of Xanthomonas campestris that is involved in xanthan gum biosynthesis. GumK belongs to the inverting GT-B superfamily and catalyzes the transfer of a glucuronic acid (GlcA) residue from uridine diphosphate (UDP)-GlcA (UDP-GlcA) to a lipid-PP-trisaccharide embedded in the membrane of the bacteria. The structure of GumK was previously described in its apo- and UDP-bound forms, with no significant conformational differences being observed. Here, we study the behavior of GumK toward its donor substrate UDP-GlcA. Turbidity measurements revealed that the interaction of GumK with UDP-GlcA produces aggregation of protein molecules under specific conditions. Moreover, limited proteolysis assays demonstrated protection of enzymatic digestion when UDP-GlcA is present, and this protection is promoted by substrate binding. Circular dichroism spectroscopy also revealed changes in the GumK tertiary structure after UDP-GlcA addition. According to the obtained emission fluorescence results, we suggest the possibility of exposure of hydrophobic residues upon UDP-GlcA binding. We present in silico-built models of GumK complexed with UDP-GlcA as well as its analogs UDP-glucose and UDP-galacturonic acid. Through molecular dynamics simulations, we also show that a relative movement between the domains appears to be specific and to be triggered by UDP-GlcA. The results presented here strongly suggest that GumK undergoes a conformational change upon donor substrate binding, likely bringing the two Rossmann fold domains closer together and triggering a change in the N-terminal domain, with consequent generation of the acceptor substrate binding site.