A dairy-based, protein-rich breakfast enhances satiety and cognitive concentration before lunch in overweight to obese young females: A randomized controlled crossover study

The purpose of this study was to investigate if consumption of a high-protein, low-carbohydrate breakfast (PRO) leads to a lower subsequent ad libitum energy intake at lunch and the rest of the day compared with ingestion of an isocaloric low-protein, high-carbohydrate breakfast (CHO) or no breakfast (CON). The study was designed as a randomized controlled 3-period crossover study. Thirty young (18-30 yr) females with overweight to obesity (body mass index >25 kg/m2) in random order completed 3 separate experimental days where they consumed either a PRO, CHO, or CON breakfast test meal followed by an ad libitum lunch meal 3 h after breakfast. Participants were allocated to a sequence group by their inclusion number. The PRO and CHO breakfasts were matched in dietary fiber and fat content. Energy intake at lunch was calculated and dietary records were obtained for the rest of the day to calculate the total daily energy intake and macronutrient intake. Ratings of appetite sensations between meals and palatability of the test meals were assessed using visual analog scale sheets in intervals ranging from 10 to 30 min. In addition, blood samples were obtained at multiple time points separated by 10 to 60 min intervals between breakfast and lunch and were analyzed for appetite-regulating gut hormones, insulin, and glucose. Finally, performance in a cognitive concentration test was tested 150 min after breakfast. Compared with CHO and CON, the area under the curves for satiety, fullness, and satisfaction in the 3 h after breakfast were significantly higher after PRO, whereas the areas under the curve for hunger, desire to eat, and prospective eating were significantly lower after PRO. The appetite-regulating gut hormones cholecystokinin, glucagon-like peptide-1, and ghrelin in the hours after breakfast, energy intake during the ad libitum lunch meal, and the total daily energy intake did not differ significantly between PRO, CHO, and CON. However, the cognitive concentration test score was 3.5 percentage points higher for PRO, but not CHO, versus CON. A dairy-based high-protein, low-carbohydrate breakfast increased satiety sensation in the hours after breakfast but did not reduce total daily energy intake compared with an isocaloric low-protein, high-carbohydrate breakfast or omitting breakfast. However, performance in a cognitive concentration test before lunch was enhanced after the high-protein, low-carbohydrate breakfast, but not the low-protein, high-carbohydrate breakfast, compared with omitting breakfast.

Dynamics of magnetization at infinite temperature in a Heisenberg spin chain

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.

Stable quantum-correlated many-body states through engineered dissipation

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

Metabolic flexibility in postmenopausal women: Hormone replacement therapy is associated with higher mitochondrial content, respiratory capacity, and lower total fat mass

AIM

To investigate effects of hormone replacement therapy in postmenopausal women on factors associated with metabolic flexibility related to whole-body parameters including fat oxidation, resting energy expenditure, body composition and plasma concentrations of fatty acids, glucose, insulin, cortisol, and lipids, and for the mitochondrial level, including mitochondrial content, respiratory capacity, efficiency, and hydrogen peroxide emission.

METHODS

22 postmenopausal women were included. 11 were undergoing estradiol and progestin treatment (HT), and 11 were matched non-treated controls (CONT). Peak oxygen consumption, maximal fat oxidation, glycated hemoglobin, body composition, and resting energy expenditure were measured. Blood samples were collected at rest and during 45 min of ergometer exercise (65% VO2 peak). Muscle biopsies were obtained at rest and immediately post-exercise. Mitochondrial respiratory capacity, efficiency, and hydrogen peroxide emission in permeabilized fibers and isolated mitochondria were measured, and citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase (HAD) activity were assessed.

RESULTS

HT showed higher absolute mitochondrial respiratory capacity and post-exercise hydrogen peroxide emission in permeabilized fibers and higher CS and HAD activities. All respiration normalized to CS activity showed no significant group differences in permeabilized fibers or isolated mitochondria. There were no differences in resting energy expenditure, maximal, and resting fat oxidation or plasma markers. HT had significantly lower visceral and total fat mass compared to CONT.

CONCLUSION

Use of hormone therapy is associated with higher mitochondrial content and respiratory capacity and a lower visceral and total fat mass. Resting energy expenditure and fat oxidation did not differ between HT and CONT.

Transcriptional determinants of lipid mobilization in human adipocytes

Defects in adipocyte lipolysis drive multiple aspects of cardiometabolic disease, but the transcriptional framework controlling this process has not been established. To address this, we performed a targeted perturbation screen in primary human adipocytes. Our analyses identified 37 transcriptional regulators of lipid mobilization, which we classified as (i) transcription factors, (ii) histone chaperones, and (iii) mRNA processing proteins. On the basis of its strong relationship with multiple readouts of lipolysis in patient samples, we performed mechanistic studies on one hit, ZNF189, which encodes the zinc finger protein 189. Using mass spectrometry and chromatin profiling techniques, we show that ZNF189 interacts with the tripartite motif family member TRIM28 and represses the transcription of an adipocyte-specific isoform of phosphodiesterase 1B (PDE1B2). The regulation of lipid mobilization by ZNF189 requires PDE1B2, and the overexpression of PDE1B2 is sufficient to attenuate hormone-stimulated lipolysis. Thus, our work identifies the ZNF189-PDE1B2 axis as a determinant of human adipocyte lipolysis and highlights a link between chromatin architecture and lipid mobilization.

Measurement-induced entanglement and teleportation on a noisy quantum processor

Measurement has a special role in quantum theory1: by collapsing the wavefunction, it can enable phenomena such as teleportation2 and thereby alter the 'arrow of time' that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time3-10 that go beyond the established paradigms for characterizing phases, either in or out of equilibrium11-13. For present-day noisy intermediate-scale quantum (NISQ) processors14, the experimental realization of such physics can be problematic because of hardware limitations and the stochastic nature of quantum measurement. Here we address these experimental challenges and study measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping9,15-17 to avoid mid-circuit measurement and access different manifestations of the underlying phases, from entanglement scaling3,4 to measurement-induced teleportation18. We obtain finite-sized signatures of a phase transition with a decoding protocol that correlates the experimental measurement with classical simulation data. The phases display remarkably different sensitivity to noise, and we use this disparity to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realizing measurement-induced physics at scales that are at the limits of current NISQ processors.

Non-Abelian braiding of graph vertices in a superconducting processor

Indistinguishability of particles is a fundamental principle of quantum mechanics¹. For all elementary and quasiparticles observed to date-including fermions, bosons and Abelian anyons-this principle guarantees that the braiding of identical particles leaves the system unchanged^2,3. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions^4-8. Hence, it can change the observables of the system without violating the principle of indistinguishability. Despite the well-developed mathematical description of non-Abelian anyons and numerous theoretical proposals^9-22, the experimental observation of their exchange statistics has remained elusive for decades. Controllable many-body quantum states generated on quantum processors offer another path for exploring these fundamental phenomena. Whereas efforts on conventional solid-state platforms typically involve Hamiltonian dynamics of quasiparticles, superconducting quantum processors allow for directly manipulating the many-body wavefunction by means of unitary gates. Building on predictions that stabilizer codes can host projective non-Abelian Ising anyons^9,10, we implement a generalized stabilizer code and unitary protocol²³ to create and braid them. This allows us to experimentally verify the fusion rules of the anyons and braid them to realize their statistics. We then study the prospect of using the anyons for quantum computation and use braiding to create an entangled state of anyons encoding three logical qubits. Our work provides new insights about non-Abelian braiding and, through the future inclusion of error correction to achieve topological protection, could open a path towards fault-tolerant quantum computing.

The hemodynamic and prognostic impact of systolic pressure change during right ventricular ejection in patients with HFREF

Background and purpose

The gold-standard method to evaluate right ventricular (RV) function in pulmonary hypertension (PH) relies on invasive pressure-volume loop (PV-loop) measurement of RV-pulmonary artery (PA) coupling defined as the ratio of end-systolic RV elastance to pulmonary arterial elastance (Ees/Ea). The normal RV PV-loop has a triangular shape with a peaking early systolic pressure (early-SP). With progression of PH the PV-loop changes from trapezoid to a rectangular and ultimately to a trapezoid shape. Along with these geometric changes, the ratio between early-SP and end-systolic pressure (ESP) decreases from >1 to <1 with a late systolic peaking of RV pressure. How all these changes relate to RV afterload, RV-PA coupling, non-invasive RV function, and prognosis in PH due to left heart disease is incomplete understood.

Methods

We analyzed and categorized the conductance catheter-derived single-beat RV PV-loops in 133 patients with HFREF (110 patients: a post-hoc analysis of the Magdeburg CRT Responder Trial, 23 from a local PV-L-derived CRT-optimization trial) according their shape (triangular, rectangular, trapezoid), and determined the early-SP/ESP ratio.

Results

Using multivariate linear regression analysis (adjusted for afterload parameter PVR, PA-compliance, PCWP, PAmean), only PCWP (beta=−0.17) and PA-compliance (beta=0.61) remained significant determinants of the early-SP/ESP ratio and PV-loop shape. In turn, early-SP/ESP ratio seems to be an important determinant of RV-PA coupling efficiency (Ees/Ea) of the RV to afterload (r=0.8, p<0.001). The association between early-SP/ESP ratio and Ees/Ea ratio was closer than Ees/Ea ratio to the other afterload parameters Ea (r=−0.7), PVR (r=−0.41), and PA-compliance (r=0.62). Furthermore, the early-SP/ESP ratio was significantly associated with parameters of non-invasive RV function such as TAPSE (r=0.67), FAC (r=0.76), RVEF (r=0.7), and the non-invasive RV-PA coupling parameter TAPSE/PASP (r=0.8) (all p<0.001). In cox regression analysis, the early-SP/ESP ratio was a strong indicator for long-term survival (median FU 4.2 years) (OR 0.025, CI 95% 0.007–0.09). Simple categorization of the RV PV-loop shapes into “triangular” (early-SP/ESP ratio >1.1, mean survival 7.7 years), “rectangular” (0.9–1.1, 6.4 years) and “trapezoid” (<0.9, 3.2 years) clearly differentiated long-term survival of HFREF patients (log rank, Chi square 50.1, p<0.001).

Conclusion

The early-SP/ESP ratio determines the shape of RV-PV-loops and is closely associated with predominately pulsatile PA load, RV-PA coupling capacity, RV function, and long-term prognosis of patients with HFREF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific

Novel echocardiographic measures of myocardial work predicts physical performance during prolonged strenuous exercise

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): The North Sea Race, Laerdal Foundation

Background

Cardiac function is a major determinant of physical performance. Cardiac function at rest can be assessed by novel echocardiographic parameters of myocardial work. Physical performance can be accurately measured using sensors recording the power output during exercise. There is limited data on the relationship between resting echocardiographic parameters and power measurements during strenuous endurance exercise. The aim of this work was to study the relationship between power output during exercise and echocardiographic parameters of cardiac structure and function at rest, including echocardiographic parameters of myocardial work.

Method

Resting echocardiographic parameters of 40 healthy, middle aged, recreational athletes, were compared with power output recordings during two episodes of endurance exercise of different duration and intensity. The first exercise was a cardiopulmonary exercise (CPX) test, which included both a lactate threshold- and a maximal oxygen uptake test. The second exercise was a 91-km mountain bike leisure sport cycling race. Power output was measured on the bikes using power meters. All study subjects were assessed by echocardiography prior to the CPX test. Coronary Computed Tomography Angiography was performed 1-2 weeks after the race to exclude obstructive coronary artery disease.

Results

Study participants were 51.1 ±9.7 years old (73 % men), median 10.0 (7.0-21.3) years of endurance training, and a median of 10.0 (5.0-20.0) endurance exercise competitions during the past five years. Both left ventricular mass and left atrial volume were in the upper reference range: 84.0 (77.0-96.0) gram/m2, 32.0 ±8.5 mL/m2, and the left ventricles were mildly dilated; 81.6 (69.1-96.5) mL/m2 (end-diastole). Median exercise duration: CPX: 43 (IQR 40-45) minutes, race: 236 (214-268) minutes. Mean heart rate; CPX: 145 ±11 bpm, race: 154 ± 10 bpm. Maximal oxygen uptake (Vo2 max): 41.6 ±9 ml/min/kg. Mean power output: CPX: 2.9 ±0.5 watt/kg, race: 2.1 ±0.5 watt/kg. There were strong bivariate correlations between left atrial and ventricular volumes and performance parameters (Table 1). Left ventricular global longitudinal strain (LV GLS) was correlated with Vo2 max. The myocardial work parameters global wasted work (GWW) and global work efficiency (GWE) were correlated with all performance parameters except Vo2 max. In multivariable linear regression models, except for VO2 max, GWW was the most consistent and strongest predictor of physical performance in all models (Table 2).

Conclusion

The novel echocardiographic parameter of global wasted work (GWW), assessed at rest, was the strongest and most consistent predictor of physical work measured by power meters during prolonged strenuous exercise.

Predictors and prognosis of RV function in pulmonary hypertension due to heart failure with reduced ejection fraction

Background and aims

Failure of right ventricular (RV) function worsens outcome in pulmonary hypertension (PH). The adaptation of RV contractility to afterload, the RV-pulmonary artery (PA) coupling, is defined by the ratio of RV end-systolic to PA elastances (Ees/Ea). Using pressure volume loop (PV-L) technique we aimed to identify an Ees/Ea cutoff predictive for overall survival and to assess hemodynamic and morphologic conditions for adapted RV function in secondary PH due to Heart Failure with Reduced Ejection Fraction (HFREF).

Methods

This post hoc analysis is based on 112 patients of the prospective Magdeburger Resynchronization Responder Trial. All patients underwent right and left heart echocardiography, and a baseline PV-L and RV catheter measurement. A subgroup of patients (n=50) without a pre-implanted cardiac device underwent MRI at baseline.

Results

The analysis revealed that 0.68 is an optimal Ees/Ea cutoff (area under the curve: 0.697, p<0.001) predictive for overall survival (median follow up = 4.7 years, Ees/Ea ≥0.68 vs. <0.68, log-rank 8.9, p=0.003. In patients with PH (n=76, 68%) Multivariate Cox-regression demonstrated the independent prognostic value of RV-Ees/Ea in PH patients (HR 0.2, p<0.038). Patients without PH (n=36, 32%) and those with PH but RV-Ees/Ea ≥0.68 showed comparable RV-Ees/Ea ratios (0.88 vs. 0.9, p=0.39), RV size/function, and survival. In contrast, secondary PH with RV-PA coupling ratio Ees/Ea <0.68 corresponded extremely close to cut-off values that define RV dilatation/remodeling (RVEDV >160ml, RV-mass/volume-ratio <0.37 g/ml) and dysfunction (RVEF <38%, TAPSE <16mm, FAC <42%, and stroke-volume/end-systolic volume ratio <0.59) and is associated with a dramatically increased short and medium-term all-cause mortality. Independent predictors of prognostically unfavorable RV-PA coupling (Ees/Ea <0.68) in secondary PH were a preexistent dilated RV (end-diastolic volume >171ml, odds ratio, OR 0.96, p=0.021), high pulsatile load (PA compliance <2.3 ml/mmHg, OR 8.6, p=0.003), and advanced systolic left heart failure (left ventricular (LV) ejection fraction <30%, OR 1.23, p=0.028).

Conclusions

The RV-PA coupling ratio Ees/Ea predicts overall survival in PH due to HFREF and is mainly affected by pulsatile load, RV remodeling and LV dysfunction. Prognostically favorable coupling (RV-Ees/Ea ≥0.68) in PH was associated with preserved RV size/function and mid-term survival, comparable to HFREF without PH.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boston Scientific

Echocardiographic parameters of myocardial work in relation to prolonged strenuous physical exercise

Background

Myocardial work (MW) assessed by echocardiography is a novel measure of left ventricular (LV) function. This measure is load-independent, and therefore a more accurate method for assessing LV function when there are changes in loading conditions. The purpose of this study was to examine alterations in MW parameters, blood pressure (BP) and LV global longitudinal strain (LV GLS) in relation to strenuous exercise, and to compare the response between two different physical stress situations.

Methods

59 healthy recreational athletes were assessed by echocardiography before-, immediately- and 24 hours after two episodes of high-intensity endurance exercise. The first exercise was a cardiopulmonary exercise (CPX) test, which included both a stepwise lactate threshold- and a maximal oxygen uptake test. The second exercise was a 91-km mountain bike leisure sport cycling competition. Global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were estimated from LV pressure-strain loops, constructed from a combination of LV GLS and non-invasive BP, using commercially available software package (Echopac V.202, GE).

Results

Subjects were 52 (43–59) years old (73% men). The duration of the CPX-test was 43 (40–45) minutes, and the race was 230 (210–245) minutes. The average heart rate during the CPX-test and the race was 144 (140–153) and 154 (148–161) beats per minute (bpm), respectively. The relative changes (percent) in systolic blood pressure (SBP) and LV GLS compared with pre-exercise values are demonstrated in Figure 1a, and GWI and GCW compared with pre-exercise values in Figure 1b. GWI at baseline was 2156 (1899–2400) mmHg% and GCW 2383 (2152–2668) mmHg%. There was a significant reduction in LV GLS (p=0.015), SBP, GWI and GCW following the CPX-test and the race (p<0.001), while there was an increase in heart rate and cardiac output (p<0.001). After the race, there was a significant (p=0.001) increase in GWW, and a reduction (p=0.006) in GWE.

Conclusion

There was a significant reduction in GWI and GCW after both the CPX-test and the race, suggesting that these markers reflect increased myocardial exhaustion following strenuous physical exercise.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by ConocoPhillips and the Simon Fougner Hartmann Trust Figure 1aFigure 1b

Left atrial function assessed by speckle tracking echocardiography predicts atrial fibrillation burden after catheter ablation independently of reconduction: a RACE-AF echocardiographic sub-study

Funding Acknowledgements

Type of funding sources: None.

Background

Left atrial (LA) function assessed by 2D speckle tracking echocardiography (STE) has demonstrated to be a useful predictor of recurrence of atrial fibrillation (AF) following catheter ablation (CA). Pulmonary vein reconduction (PVR) is one of the most important causes of recurrent paroxysmal AF (PAF) after ablation. The purpose of this study was to evaluate the association between AF burden (% of time in AF) following CA and LA strain measurements independently of PVR.

Methods

This prospective study included 66 patients with PAF who underwent CA (mean age 60 ± 8 years, 65% male). STE was performed during sinus rhythm prior to CA. AF burden was recorded by continuous rhythm monitoring using implantable loop recorders during a follow-up period of 4-6 months, excluding a blanking period of 3 months. After follow-up, all patients underwent an invasive assessment of pulmonary vein isolation to test for PVR. Multivariable linear regression analysis was used to assess the association between AF burden and peak atrial longitudinal reservoir strain (PALS), peak atrial contraction strain (PACS) and peak atrial conduit strain (PCS).

Results

Prior to CA, median AF burden was 3.8% (IQR: 0.5, 17). During follow-up, 37 patients (56%) were free of AF while median AF burden was 0.7% (IQR: 0.2, 1.6) in patients with an AF burden of more than 0%. A total of 35 patients (54%) were found to have PVR after ablation. Patients with AF recurrence had significantly lower PACS compared to patients with no AF during follow-up (10% ± 6% vs. 14% ± 5%, p = 0.004). No differences in PALS and PCS were observed. Increased PACS remained independently associated with low AF burden following CA after multivariable adjustments for clinical characteristics, comorbidities, and PVR (β=-0.262, p = 0.049) (Figure 1). PALS and PCS did not remain significantly associated with AF burden.

Conclusion

Increased PACS is strongly associated with low AF burden after CA even after adjusting for PVR. This suggests that an analysis of LA function could be useful to stratify patients prior to CA and improve treatment strategies.

Abstract Figure.

Review of Potentially Toxic Rare Earth Elements, Thallium and Tellurium in Plant-based Foods

In the last decades, there is an increasing inclusion of various trace metals and metalloids such as thallium, tellurium and rare earth elements (REEs; lanthanides, scandium, and yttrium) in the composition and production of alloys, in agricultural and medicinal applications, as well as in the manufacturing of hi-tech products. All these activities have led to an accumulation of the aforementioned elements both in soil and water bodies and consequently in the food chain, through discharges from mining and mineral processing, liquid industrial waste or disposal of urban and industrial products. It has been demonstrated that chronic exposure to some of these elements, even at low doses, might lead to a wide range of adverse health effects, even from the early stages of life, such as neurotoxicity, neurodevelopmental toxicity and hepatic alterations. Particularly in children, there have been studies suggesting that some of these elements might negatively affect the children's spatial learning and memory ability indirectly. Such effects are triggered by processes like the production of reactive oxygen species (ROS), lipid peroxidation and modulation of antioxidant activities. Nevertheless, the limited data from toxicological studies and their so-far naturally low occurrence levels in the environment acted as a deterrent in measuring their concentrations during routine analyses of metals in foodstuff. Thus, it is important to collect information on their occurrence data both in adults and in children's daily diet. This review sumrises the current knowledge on the concentration of these elements, in plant-based food products to identify whether a potential health risk occurs. As side projects, this Fellowship provided hands-on training on the evaluation of new biocides application and participation in the given advice to the Danish Food and Veterinary Administration, Danish Environmental Protection Agency, the Danish Medical Agency and the European Chemicals Agency.

Right ventricular pulmonary vascular coupling in secondary tricuspid regurgitation: a pressure volume loop study

Introduction

The severity of secondary tricuspid regurgitation (sTR) predicts outcome of patients with left heart failure with reduced ejection fraction (HFrEF). In these patients sTR predominantly occurs as a result of secondary pulmonary hypertension (PH). However, more than 46% of patients with severe PH have only mild or none sTR. In this study we tested the hypothesis that intrinsic right ventricular (RV) contractility adaptation to the pulmonary arterial (PA) vascular load (RV-PA-coupling) is associated with the presence and severity of sTR.

Methods

In 110 patients with HFrEF (a post-hoc analysis of the Magdeburger CRT Responder Trial, DRKS00011133) we quantified the RV intrinsic contractility response (end-systolic elastance, Ees) to pulmonary vascular afterload (arterial elastance, Ea) and its coupling ratio (RV-PA coupling ratio: Ees/Ea) by the RV pressure-volume loop catheter technique at baseline, and combined it with echocardiography-derived parameter of sTR presence and severity and RV function.

Results

Echocardiography at baseline demonstrated no or trace TR (TR0) in 67 patients (61%), mild TR (TR1) in 23 (21%), moderate TR (TR2) in 11 (10%), and severe TR (TR3) in 9 (8%). The transition from TR0 to TR1 was characterized by a pronounced drop of the RV-PA coupling ratio (TR0: Ees/Ea= 0.88, 0.67–1.1 vs. TR1: Ees/Ea= 0.48, 0.3–0.83, p<0.001), caused by a non-adaptive, non-rising Ees (0.24 mmHg/ml, 0.34–0.44 vs. 0.3 mmHg/ml, 0.21–0.46, p=0.8, respectively, p<0.001). We observed a further but only marginal drop of Ees/Ea from TR1 to TR3 (p=0.008) caused by an additional small non-significant decrease of Ees and increase of Ea. Interestingly, other afterload parameter, such as PA-pressure, wedge pressure (PCWP), PA compliance, and PA resistance (PVR), and parameters of RV function, such as tricuspid annular plane systolic excursion (TAPSE) and fractional area shortening (FAC) followed the same course of a pronounced drop from TR0 to TR1, succeeded by an only marginal change from TR1 to TR3. In contrast, the progressive RV-PA un-coupling from TR0 to TR3 was accompanied by a more or less continuously increase of RV size and volume load (end-diastolic (ED) area in 4 chamber view, ED-RV outflow tract diameter, size of tricuspid annulus). In the binary logistic regression analysis, the decrease of RV-PA coupling ratio Ees/Ea (OR 0.14, CI 0.001–0.165) and PA compliance (OR 0.44, CI 0.25–0.79) were independently associated with the transition from TR0 to TR1–3.

Conclusion

The presence and severity of secondary TR in patients with HFREF is independently associated with a progressive RV-PA uncoupling. Most importantly, already the transition from none TR to mild TR is characterized by a significant and pronounced increase of pulmonary vascular afterload, a non-adaptive RV contractility response, and resulting RV-PA un-coupling.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Boston Scientific

Lexical analysis of emotional responses to "real-world" experiences in individuals with schizophrenia

Abnormalities in emotion perception, expression, and experience are considered a core component of schizophrenia. Previous laboratory studies have demonstrated that while individuals with schizophrenia report levels of positive emotions comparable to healthy individuals in response to positive stimuli, they also report co-occurring negative emotions in response to such stimuli. However, it is unknown whether this response pattern extends to "real world" naturalistic environments. To examine this question, we employed an experience sampling method (ESM) approach using mobile electronic devices to collect information up to 10 times/day over a two-day period from 53 individuals with schizophrenia and 19 non-clinical controls. As part of each experience sample, participants completed brief open-ended responses and answered questions about their emotional responses to three recent events (neutral, positive, and negative). Additionally, participants completed diagnostic and clinical measures. Lexical analyses were used to analyze ESM-based word production and characterize emotion word use. Compared to non-clinical controls, individuals with schizophrenia reported similar levels of positive emotion, but significantly higher negative emotion, which was associated with increased negative symptoms. The schizophrenia group used more anxiety words in response to negative and neutral events, and more anger words in response to positive events. Increased use of anger words was linked with elevations in positive symptoms as well as symptoms of depression, while use of sadness words was linked with anhedonia. Our findings support the co-activation of negative emotion hypothesis documented in laboratory settings and provide evidence of its ecological validity. Implications for functioning and future directions are discussed.

Substrate Supporting Disc Method for Confirmed Detection of Total Coliforms and E. coli in all Foods: Collaborative Study

The Coli Complete® substrate supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with AOAC most probable number (MPN) methods, 966.23 and 966.24. Twenty-nine laboratories participated in this collaborative study in which 6 food types were analyzed. Four food types, raw ground beef, pork sausage, raw liquid milk, and nut meats, were naturally contaminated with coliform bacteria. Two foods, dry egg and fresh frozen vegetables, were seeded with coliforms. Three food types, ground beef, raw liquid milk, and pork sausage, were naturally contaminated with E. coli. Although pork sausage was naturally contaminated, the level was very low (<10/50 g); therefore, additional E. coli were inoculated into 1 lot of this food type. Three food types, nut meats, dry egg, and fresh frozen vegetables, were inoculated with E. coli. For naturally contaminated samples, duplicate determinations were made on 3 separate lots for each food type. For inoculated samples, low, medium, and high contamination levels plus uninoculated control samples were examined in duplicate. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN method. Results were then analyzed for repeatability, reproducibility, and mean log MPN statistical equivalence. Results were statistically equivalent for all total coliform levels in all food types except frozen vegetable and raw nut meat uninoculated control samples and 1 lot of pork sausage where the SSD method produced statistically significant greater numbers. For the E. coli determinations, results were statistically equivalent across all samples and all levels for each food type. The SSD method has been adopted first action by AOAC International for confirmed detection of total coliforms and E. coli in all foods.

Secondary traumatisation, burn-out and functional impairment: findings from a study of Danish child protection workers

Background: Child-protection workers are at elevated risk for secondary traumatization. However, research in the area of secondary traumatization has been hampered by two major obstacles: the use of measures that have unclear or inadequate psychometric properties and equivocal findings on the degree of associated functional impairment. Objective: To assess the relationship between secondary traumatization and burnout using exploratory structural equation modelling (ESEM) and to assess the relationship between secondary traumatization and functional impairment. Methods: A survey of Danish child-protection workers was conducted through the Danish Children Centres (N = 667). Secondary traumatization was measured using the Professional Quality of Life-5 (ProQoL-5) and burnout using the Oldenburg Burnout Inventory. Results: A three-factor ESEM model provided the best fit to the data, reflecting factors consistent with the structure of secondary traumatization and burnout. The factors were differentially related to trauma-related and organizational variables in ways consistent with existing evidence. All factors were significantly related to functional impairment. Conclusion: The findings supported the discriminant validity of secondary traumatization and burnout while highlighting methodological issues around the current use of sum-score approaches to investigating secondary traumatization. The current study supported the clinical relevance of secondary traumatization by linking it explicitly to social and cognitive functional impairment.

P4687Relevance of TAPSE and FAC, and their relationship to PASP as echo-derived measures for RV-PA coupling in heart failure: a comparative analysis with invasive RV-pressure volume loop data

Background

Right ventricular (RV) to pulmonary artery (PA) coupling (C), quantified by pressure volume (PV) loop analysis, predicts RV function, and is independently associated with long term survival in systolic heart failure (HFrEF). However, the PV loop technique is invasive and complex to carry out, especially when used to do RV functional analyses. Different echo-surrogate parameters are proposed to measure RV-PA-C, such as the tricuspid annular plane systolic excursion, TAPSE/PAsystolic pressure (SP) and FAC (fractional area change)/PASP as the most promising parameters. However, up to now, no validation of these non-invasive coupling indices with the invasive gold standard method of RV-PV-loops has been done.

Methods

In 111 patients with advanced HFrEF (Post-hoc analysis of Magdeburger CRT Responder Trial, DRKS00011133), echo-derived TAPSE and FAC, and their relationship to PASP were related to the RV PV-loop-derived parameters of intrinsic RV contractility (Ees), pulmonary load (Ea), and the RV-PA-C efficiency (Ees/Ea) by linear regression analysis. Within a MRI substudy (n=49 patients) we examined the relationship of pure longitudinal contraction (MRI-TAPSE) and radial free wall to septum contraction (area change of 5 RV segments from tricuspid valve to apex in the short axis view) to the invasive RV-PA-C.

Results

The MRI analysis demonstrated that radial RV contraction (R2=0.77, p<0.001) correlated better to invasive RV-PA-C than pure longitudinal shortening (R2=0.37, p<0.001) (radial vs. longitudinal: p<0.00). Echo data for the entire patient cohort confirmed the MRI data. The FAC (R2=0.8, p<0.001) was significantly better associated with RV-PA-C than TAPSE (R2=0.57, p<0.001) (TAPSE vs FAC, p<0.001). Placing TAPSE or FAC into a quotient with PASP did not at all (TAPSE vs. TAPSE/PASP, p=0.1) or significantly attenuated (FAC vs. FAC/PASP R2=0.8 vs 0.58, p<0.001) their association to RV-PA-C. However, FAC/PASP and TAPSE/PASP correlated significantly better with global afterload (Eea), PA compliance, and pressure volume area (PVA), (p<0.001). In ROC analysis for all-cause mortality, all 4 tested parameters were prognostic relevant, however, with higher AUC values for FAC/PASP (AUC=0.74, p<0.001) and TAPSE/PASP (AUC=0.74, p<0.001) than for single TAPSE (AUC= 0.71, p=0.001) or FAC (AUC=0.7, p=0.001). Within a multivariate Cox regression analysis, only the FAC/PASP remained an independent predictor for long term survival.

Conclusion

FAC, an echo parameter that includes a predominant radial with a smaller part of longitudinal contraction, correlated significantly better to the invasively derived RV-PA-C-ratio than pure longitudinal RV shortening (TAPSE). Combining FAC or TAPSE with PASP did not improve the non-invasive RV-PA coupling information. However, it provided more comprehensive information on pulmonary vascular load and RV oxygen consumption, which seems to be translated into a higher prognostic power.

Acknowledgement/Funding

scientific grant from Boston Scientific

Are vitamins A and E associated with persistent organic pollutants and fatty acids in the blubber of highly contaminated killer whales (Orcinus orca) from Greenland?

We quantified blubber concentrations of vitamins A (retinol) and E (α-tocopherol) and evaluated associations with persistent organic pollutants (ΣPOPs) in 14 highly-contaminated killer whales (Orcinus orca) sampled in Greenland from 2012 to 2014. We considered the influence of blubber depth, sex/age class and diet (based on biomass % of major fatty acids) in these relationships. Blubber concentrations of vitamin A averaged 34.1 ± 4.7 μg g^-1 wet weight (ww) and vitamin E averaged 35.6 ± 4.4 μg g^-1 ww. Although overall vitamin A concentrations did not vary between inner (closer to the muscle) and outer (closer to the skin) blubber layer or between sub-adults and adult females, concentrations in the outer layer of sub-adults were lower compared to the outer layer of adult females (p = 0.03). Outer layer may therefore reflect age accumulation of vitamin A, while in the more active inner layer, age effects might be masked by metabolic needs such as lactation. Neither diet nor ΣPOPs affected vitamin A variation, suggesting this vitamin is highly regulated in the body. Given the high exposures in these killer whales, vitamin A might not be a sensitive biomarker for POPs adverse effects. Vitamin E concentrations were significantly higher in inner compared to outer layer (p < 0.001), likely associated with blubber composition, suggesting that biopsies may not fully represent vitamin E concentrations in blubber. Age-accumulation of vitamin E also occurred with higher concentrations in adult females compared to sub-adults, independent of blubber depth (p < 0.01). Diet, ΣPOPs, and an interaction between these two variables significantly affected vitamin E variation in inner blubber, explaining 91% of this variation. The negative relationship between ΣPOPs (especially Σdichlorodiphenyltrichloroethane (DDT) and Σchlordanes in outer layers) and vitamin E was observed only in killer whales with a diet poorer in polyunsaturated fatty acids, suggested that killer whales feeding more consistently on marine mammals in Arctic environments over a fish-based diet, may be at higher risk of POP-induced disruption in vitamin E homeostasis. Considering diet is therefore important to understand the potential effects of elevated contaminant exposures on levels of certain essential nutrients, i.e., vitamin E, in killer whales.

Analysis and Risk Assessment of Seaweed

During the last decade, the interest on the use of seaweed as food or feed, which was before limited to certain European regional subpopulations, has experienced a significant increase in other regions of the EU. In fact, the growing awareness and interest on sustainable and alternative food sources, healthier lifestyles and changes on dietary patterns brought seaweed to the spotlight for the general worldwide cuisine. Due to their high biosorption and accumulation capacity, seaweed can be an important source of increased exposure to persistent and potential harmful elements, such as cadmium (Cd), lead (Pb), mercury (Hg) and inorganic arsenic (iAs), or even some micronutrients, particularly iodine (I), to which an antioxidant role as been described in seaweed. This concentration potential has raised the interest of several Food Authorities regarding the risk of increased exposure to these elements. Moreover, the European Commission requested the collection of monitoring data on their levels aiming to aid the performance of better risk assessments and potentially set maximum levels on the European Legislation. This work aimed to obtain levels of these elements in species of seaweed (Fucus vesiculosus, Fucus serratus, Fucus spiralis, Fucus evanescens, Saccharina latissima, ulva lactuca and Ccladophora sp.) cultivated and harvested in Denmark, following European Commission's request. Additionally, a collaboration between Denmark, Ireland, France and the Netherlands was initiated to review and collect all the data available on scientific papers regarding the levels of these contaminants in seaweed worldwide. The final result of this work would be the publication of a review article. This Fellowship also provided on‐the‐job training on the evaluation of applications of new biocides and participation in the science based advises given to the Danish Food and Veterinary Administration, Danish EPA, the Danish Medical Agency and ECHA.

Modeling variation of clinical team processes with multiple sequence alignment

Our objective was to model process variation of Emergency Medical Service teams responding to simulated pediatric emergencies and determine if sequence alignment distinguishes performance quality. We performed a retrospective process analysis by watching and coding activities in videos from standardized simulations of 42 Emergency Medical Service teams. Teams were classified into high- or low-performing groups based on the Clinical Teamwork Scale™. Activities were coded according to resuscitation tasks, performer, and times. We used ClustalG to align task sequences within and between groups, and measured similarity. Teams within and between performance levels had an average sequence similarity of 52 ± 7% and 50 ± 7%. Teams performed clinically appropriate tasks that varied in prioritization, for example, performing compressions or connecting the EKG monitor early. There was no statistical difference in gross similarity between groups but specific differences in prioritization may have had clinically meaningful implications. Alignment could improve by accounting for task duration and concurrency.

Obesity leads to impairments in the morphology and organization of human skeletal muscle lipid droplets and mitochondrial networks, which are resolved with gastric bypass surgery-induced improvements in insulin sensitivity

AIMS

Skeletal muscle lipid stores and mitochondrial function have been appointed as key players in obesity-induced insulin resistance. However, there are conflicting reports in the literature based on in vitro quantitative measurements. Here, we test the hypothesis that it is not the quantity but the quality that matters.

METHODS

This study combines quantitative and qualitative structural measurements of lipid stores and mitochondrial dynamics in skeletal muscle from lean subjects, and subjects with morbid obesity, with and without type 2 diabetes, before and after gastric bypass surgery.

RESULTS

The structural organization of muscle mitochondrial networks in type II muscle fibres from subjects with morbid obesity is impaired. In addition, the amount of skeletal muscle perilipin 2 protein per intramyocellular lipid is reduced in subjects with morbid obesity, resulting in qualitative alterations in perilipin 2 coat around some lipid droplets. Gastric bypass surgery-induced weight loss and insulin resistance remission were associated with decreases in intramyocellular lipid stores and, qualitative improvements in lipid droplets' morphology, perilipin 2 coat and mitochondrial dynamics.

CONCLUSION

Morbid obesity leads to severe qualitative alterations of both skeletal muscle lipid stores and mitochondrial networks. The degree of structural improvements after gastric bypass surgery was proportional to the improvements in whole body insulin sensitivity, suggesting an association between these events.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Mood disorder in the personal correspondence of Robert Burns: testing a novel interdisciplinary approach

Robert Burns has long been recognised as someone who experienced episodes of melancholia, but no detailed, systematic and objective assessment of his mental health has been undertaken. We tested a novel methodology, combining psychiatric and literary approaches, to assess the feasibility of using Burns's extensive personal correspondence as a source of evidence for assessing the presence of symptoms of a clinically significant mood disorder. We confirmed the potential of this approach and identified putative evidence of episodes of depression and hypomania within the correspondence. While not conclusive of a formal diagnosis of bipolar disorder, this work highlights a need for further systematic examination of Burns's mental health and how this may have influenced his work.

Endothelial dysfunction following coronary artery bypass grafting : Influence of patient and procedural factors

BACKGROUND

Angiopoietin-2 (Angpt2) mediates endothelial dysfunction (ED) following coronary artery bypass grafting (CABG). Its triggers are, however, poorly understood.

METHODS

We examined the time course of ED beyond the early phase of postoperative recovery in 75 patients following CABG with a special focus on different cardiopulmonary bypass (CPB) modes as potential triggers of Angpt2 release.

RESULTS

Nine patients (12.0%) underwent off-pump coronary artery bypass (OPCAB), 31 patients (41.3%) received minimized extracorporeal circulation (MECC), and 35 patients (46.6%) were operated on with (conventional) CPB. Angpt2 levels steadily increased across the observation period (1.7 [1.4-2.1] to 3.4 [2.5-6.1] ng/ml, p < 0.001). Angpt2 levels did not differ between the MECC and CPB groups (p = 0.564). There was no difference between MECC and CPB patients regarding net fluid balance (p = 0.821) and other surrogate markers of postoperative ED. The magnitude of Angpt-2 increase correlated more strongly with baseline C‑reactive protein (r = 0.459, p < 0.001) than with any other parameter. Hospital length of stay correlated more strongly with baseline Angpt2 levels (r = 0.512, p = 0.005) than with follow-up Angpt2 levels and appeared not to be influenced by CPB mode (p = 0.428).

CONCLUSION

CABG is associated with prolonged ED, which is determined by the patient's preoperative inflammatory state rather than by CPB modifications.

Mitochondrial respiratory capacity remains stable despite a comprehensive and sustained increase in insulin sensitivity in obese patients undergoing gastric bypass surgery

AIM

It has been proposed, but not yet demonstrated by convincing evidence in published articles, that insulin resistance and mitochondrial respiratory function are causally related physiological phenomena. Here, we tested the prediction that weight loss-induced increase in insulin sensitivity will correlate with a corresponding change in mitochondrial respiratory capacity over the same time period.

METHODS

Insulin sensitivity was evaluated using the hyperinsulinaemic-euglycaemic clamp technique, and skeletal muscle mitochondrial respiratory capacity was evaluated by high-resolution respirometry in 26 patients with obesity. Each experiment was performed ~2 months and 1-2 weeks before, and ~4 and ~19 months after Roux-en-Y gastric bypass (RYGB) surgery.

RESULTS

A substantial weight loss was observed in all patients, and insulin sensitivity increased in all patients over the 21-months time period of the study. In contrast, skeletal muscle mitochondrial respiratory capacity, intrinsic mitochondrial respiratory capacity and mitochondrial content remained unchanged over the same time period.

CONCLUSION

Among obese patients with and without type 2 diabetes undergoing RYGB surgery, intrinsic mitochondrial respiratory capacity in skeletal muscle is not correlated with insulin sensitivity before or after the surgical intervention. Mitochondrial respiratory function may not be germane to the pathophysiology and/or aetiology of obesity and/or type 2 diabetes.

Elimination of Meropenem by Continuous Hemo(Dia) Filtration: An in Vitro One-Compartment Model

Meropenem is a carbapenem antibiotic with a wide spectrum of activity against most gram positive and gram negative bacteria including anaerobes. Dose adjustments are necessary during continuous renal replacement therapies of acute renal failure. This in vitro study was conducted to investigate the influence of different filter materials, surface areas (AN-69 0.6 m2 and 0.9 m2, polysulfone 0.75 m2, polyamide 0.6 m2), and increasing flow rates (from 3.3 - 26.7 ml/min) on the elimination of meropenem in an in vitro continuous hemo(dia)filtration model. Meropenem was measured using HPLC with UV-detection. While the clearance increased proportionally to increasing dialysate flow rates in filters with a surface area of 0.9 m2, a peak clearance was reached in the small filters at flow rates of 10.0 ml/min (polyamide 0.6 m2) and 18.3 ml/min (AN-69 0.6 m2), when tested under the same conditions. This indicated incomplete dialysate saturation due to the diminished time available for meropenem to equilibrate with the dialysate solution. No adsorption to either of the tested membranes was detected. Dosage recommendations derived from clinical studies might be appropriate when different filter materials, but similar operational settings of the continuous replacement therapy, are applied. Reduction of the recommended dose might be necessary, when renal replacement therapies with lower flow rates and/or filters with smaller surface areas are carried out.

Self-Tracking, Social Media and Personal Health Records for Patient Empowered Self-Care

This paper explores the range of self-tracking devices and social media platforms used by the self-tracking community, and examines the implications of widespread adoption of these tools for scientific progress in health informatics.

A literature review was performed to investigate the use of social media and self-tracking technologies in the health sector. An environmental scan identified a range of products and services which were used to exemplify three levels of self-tracking: self-experimentation, social sharing of data and patient controlled electronic health records.

There appears to be an increase in the use of self-tracking tools, particularly in the health and fitness sector, but also used in the management of chronic diseases. Evidence of efficacy and effectiveness is limited to date, primarily due to the health and fitness focus of current solutions as opposed to their use in disease management.

Several key technologies are converging to produce a trend of increased personal health surveillance and monitoring, social connectedness and sharing, and integration of regional and national health information systems. These trends are enabling new applications of scientific techniques, from personal experimentation to e-epidemiology, as data gathered by individuals are aggregated and shared across increasingly connected healthcare networks. These trends also raise significant new ethical and scientific issues that will need to be addressed, both by health informatics researchers and the communities of self-trackers themselves.

Towards Addressing the Opportunities and Challenges of Web 2.0 for Health and Informatics

ObjectiveTo provide an overview of Web 2.0 and Health 2.0, and so facilitate a widespread discussion of the nature of these concepts and their possible application within the health domain, and implications for health and biomedical informatics and for IMIA.

MethodsIMIA, the International Medical Informatics Association, has established a Web 2.0 Exploratory Taskforce to bring together interested individuals from within and outside IMIA to explore the nature and potential of Web 2.0 applications. The Taskforce aims to develop background materials and sample uses of Web 2.0 applications, so as to propose specific lines of action for the IMIA Board and General Assembly. This paper provides a brief overview of Web 2.0 and related concepts, and examples of general and health-specific Web 2.0 applications. Some examples of the issues, challenges and opportunities are introduced, to set the scene for a wider dialogue on if, how, and how best, IMIA, and the wider health and informatics communities, should use these new applications and approaches.

Results and conclusionsThis brief paper provides an introduction to, and overview of, the many issues involved in considering the application of Web 2.0 to health and informatics. All interested individuals and organisations are invited to use this as a starting point for engaging in wider discussion and contributing to the Taskforce and to IMIA’s future.

Experience in the Use of Social Media in Medical and Health Education

Social media are online tools that allow collaboration and community building. Succinctly, they can be described as applications where “users add value”. This paper aims to show how five educators have used social media tools in medical and health education to attempt to add value to the education they provide.

We conducted a review of the literature about the use of social media tools in medical and health education. Each of the authors reported on their use of social media in their educational projects and collaborated on a discussion of the advantages and disadvantages of this approach to delivering educational projects.

We found little empirical evidence to support the use of social media tools in medical and health education. Social media are, however, a rapidly evolving range of tools, websites and online experiences and it is likely that the topic is too broad to draw definitive conclusions from any particular study. As practitioners in the use of social media, we have recognised how difficult it is to create evidence of effectiveness and have therefore presented only our anecdotal opinions based on our personal experiences of using social media in our educational projects.

The authors feel confident in recommending that other educators use social media in their educational projects. Social media appear to have unique advantages over non-social educational tools. The learning experience appears to be enhanced by the ability of students to virtually build connections, make friends and find mentors. Creating a scientific analysis of why these connections enhance learning is difficult, but anecdotal and preliminary survey evidence appears to be positive and our experience reflects the hypothesis that learning is, at heart, a social activity.

Elimination of Linezolid by an in vitro Extracorporeal Circuit Model

Linezolid is an oxazolidinone antibiotic with activity against important grampositive aerobic bacteria, including nosocomial pathogens. It is not known whether dosage adjustments are necessary in patients treated with continuous renal replacement therapies. This in vitro study was conducted to investigate the elimination of linezolid in an in vitro continuous hemo(dia)filtration model using different filter materials (polysulfone, polyacrylonitrile, polyamide), surface areas, and different modes of renal replacement therapies. Linezolid was measured using HPLC with UV-detection. No adsorption of linezolid to any of the tested membranes was detected. Recovery of linezolid in the ultrafiltrate was 98.2 ± 10.5% in the filtration mode. During dialysis, recovery was significantly less (87.6 ± 16.1%; p = 0.02). Linezolid elimination was not altered by filter size, when polysulfone filters with surface areas of 0.7 m2 and 1.3 m2 were tested. In conclusion, the dosage recommendations for linezolid are independent of the filter materials. However, the elimination is significantly higher during hemofiltration compared to dialysis.

Mechanism-Based Modeling of Gastric Emptying Rate and Gallbladder Emptying in Response to Caloric Intake

Bile acids released postprandially modify the rate and extent of absorption of lipophilic compounds. The present study aimed to predict gastric emptying (GE) rate and gallbladder emptying (GBE) patterns in response to caloric intake. A mechanism‐based model for GE, cholecystokinin plasma concentrations, and GBE was developed on data from 33 patients with type 2 diabetes and 33 matched nondiabetic individuals who were administered various test drinks. A feedback action of the caloric content entering the proximal small intestine was identified for the rate of GE. The cholecystokinin concentrations were not predictive of GBE, and an alternative model linking the nutrients amount in the upper intestine to GBE was preferred. Relative to fats, the potency on GBE was 68% for proteins and 2.3% for carbohydrates. The model predictions were robust across a broad range of nutritional content and may potentially be used to predict postprandial changes in drug absorption.

Predictors of responses to immune checkpoint blockade in advanced melanoma

Immune checkpoint blockers (ICB) have become pivotal therapies in the clinical armamentarium against metastatic melanoma (MMel). Given the frequency of immune related adverse events and increasing use of ICB, predictors of response to CTLA-4 and/or PD-1 blockade represent unmet clinical needs. Using a systems biology-based approach to an assessment of 779 paired blood and tumor markers in 37 stage III MMel patients, we analyzed association between blood immune parameters and the functional immune reactivity of tumor-infiltrating cells after ex vivo exposure to ICB. Based on this assay, we retrospectively observed, in eight cohorts enrolling 190 MMel patients treated with ipilimumab, that PD-L1 expression on peripheral T cells was prognostic on overall and progression-free survival. Moreover, detectable CD137 on circulating CD8⁺ T cells was associated with the disease-free status of resected stage III MMel patients after adjuvant ipilimumab + nivolumab (but not nivolumab alone). These biomarkers should be validated in prospective trials in MMel.The clinical management of metastatic melanoma requires predictors of the response to checkpoint blockade. Here, the authors use immunological assays to identify potential prognostic/predictive biomarkers in circulating blood cells and in tumor-infiltrating lymphocytes from patients with resected stage III melanoma.

Ethical Issues of Social Media Usage in Healthcare

OBJECTIVE

Social media, web and mobile technologies are increasingly used in healthcare and directly support patientcentered care. Patients benefit from disease self-management tools, contact to others, and closer monitoring. Researchers study drug efficiency, or recruit patients for clinical studies via these technologies. However, low communication barriers in socialmedia, limited privacy and security issues lead to problems from an ethical perspective. This paper summarizes the ethical issues to be considered when social media is exploited in healthcare contexts.

METHODS

Starting from our experiences in social-media research, we collected ethical issues for selected social-media use cases in the context of patient-centered care. Results were enriched by collecting and analyzing relevant literature and were discussed and interpreted by members of the IMIA Social Media Working Group.

RESULTS

Most relevant issues in social-media applications are confidence and privacy that need to be carefully preserved. The patient-physician relationship can suffer from the new information gain on both sides since private information of both healthcare provider and consumer may be accessible through the Internet. Physicians need to ensure they keep the borders between private and professional intact. Beyond, preserving patient anonymity when citing Internet content is crucial for research studies.

CONCLUSION

Exploiting medical social-media in healthcare applications requires a careful reflection of roles and responsibilities. Availability of data and information can be useful in many settings, but the abuse of data needs to be prevented. Preserving privacy and confidentiality of online users is a main issue, as well as providing means for patients or Internet users to express concerns on data usage.

Synovial incorporation of polyacrylamide hydrogel after injection into normal and osteoarthritic animal joints

OBJECTIVE

Polyacrylamide hydrogel (PAAG) is a non-toxic, non-degradable synthetic product, used for years in the augmentation of soft tissues. Preliminary results in animals and humans have suggested long-lasting beneficial effects on symptoms of osteoarthritis (OA). The aim of this histopathological study was to investigate whether intra-articular injection of PAAG is integrated into synovial tissue in normal and OA animal joints, and if this integration is sustained.

METHODS

(A) A prospective, controlled, longitudinal study of normal knee joints injected with PAAG was performed in 10 rabbits, following the animals up to 1 year, and (B) a post mortem examination was carried out up to 2 years post-injection on 18 horse joints which had previously been treated with 1-2 injections of 2 ml PAAG for clinically and radiologically diagnosed OA.

RESULTS

Integration of the injected gel was evident at day 10 in the rabbit and by day 14 in the horse, with proliferation and invasion of synovial cells into the gel. By day 90 in rabbit joints and day 30 in horse joints, the gel had formed a sub-synovial layer, which was traversed by thin strands of connective tissue with vessels and covered by a synovial lining facing the joint cavity. This histological appearance persisted up to 2 years post-injection in horse joints.

CONCLUSION

Intra-articular injection of PAAG results in a stable, long-lasting sub-synovial layer of gel traversed with thin strands of connective tissue. Further studies to explore potential effects on synovial inflammation and pain are warranted.

Factor VIII chromogenic assays can be used for potency labeling and postadministration monitoring of N8-GP

Essentials Chromogenic assays may be less variable than one-stage clot assays for measuring modified factor VIII. Chromogenic assays were evaluated for N8-GP potency labeling and postadministration monitoring. There was no significant difference between chromogenic assay kits for measuring N8-GP potency. Postadministration monitoring of N8-GP was comparable to turoctocog alfa for all kits tested.

SUMMARY

Background Factor VIII activity (

FVIII

C) is commonly measured using one-stage activated partial thromboplastin time (aPTT)-based clot assays. Chromogenic assays are, however, an alternative, and potency assessment in Europe is performed using chromogenic assays. One-stage clot assays are in general associated with high variability, and modified FVIII products may add to this variability. FVIII chromogenic assays may be less affected. Objectives To evaluate available chromogenic assay kits for potency labeling of polyethylene glycol-glycoconjugated turoctocog alfa (turoctocog alfa pegol [N8-GP]) and to evaluate selected chromogenic kits for postadministration monitoring of N8-GP using turoctocog alfa (Novoeight(®) ) as comparator. Methods Six FVIII chromogenic assay kits were adapted to the European Pharmacopeia guidelines for potency labeling, including assessment of time to 50% FX activation. Four kits were adapted for postadministration monitoring using an ACL(®) TOP 500 analyzer. Severe hemophilia A plasma was spiked with N8-GP or turoctocog alfa to simulate postadministration samples. The World Health Organization (WHO) 8th International Standard (IS) FVIII concentrate was used as calibrator throughout. In addition, a plasma calibrator was used for postadministration samples. Results When measuring N8-GP potency, no significant difference using a 1% significance level was observed between kits. In simulated postadministration samples, all test kits were highly accurate and precise, except at low concentrations, with no significant difference between

FVIII

C (P > 0.05) measured using the different calibrators. However, values obtained using the WHO 8th IS were closer to labeled values. Conclusions Chromogenic assay kits tested measured consistent

FVIII

C for N8-GP potency and showed comparable results for N8-GP and turoctocog alfa in simulated postadministration samples.