Coherent Subcycle Optical Shock from a Superluminal Plasma Wake

We propose exploiting the superluminal plasma wake for coherent Cherenkov radiation by injecting a relativistic electron beam (REB) into a plasma with a slowly varying density up-ramp. Using three-dimensional particle-in-cell and far-field time-domain radiation simulations, we show that an isolated subcycle pulse is coherently emitted towards the Cherenkov angle by bubble-sheath electrons successively at the rear of the REB-induced superluminal plasma wake. A theoretical model based on a superluminal current dipole has been developed to interpret such coherent radiation, and agrees well with the simulation results. This radiation has ultrashort attosecond-scale duration and high intensity, and exhibits excellent directionality with ultralow angular divergence and stable carrier envelope phase. Its intensity increases with the square of the propagation length and its central frequency can be easily tuned over a wide range, from the far infrared to the ultraviolet.

Initial Results of a Phase II Trial of Hypofractionated Radiation Therapy for Inoperable Soft Tissue Sarcoma

PURPOSE/OBJECTIVE(S)

For patients with soft tissue sarcoma (STS) who cannot or choose not to have surgery, radiation can provide local tumor control in both palliative and definitive settings. Conventionally fractionated radiation provides modest (< 50%) rates of local control (LC) for STS at 2 years. To our knowledge, no prospective studies to date have evaluated the safety and efficacy of dose-escalated hypofractionated radiation therapy as treatment of inoperable STS. We hypothesized that dose-escalated, hypofractionated radiation therapy (RT) for inoperable STS could achieve higher rates of LC than reported in trials of conventionally fractionated RT.

MATERIALS/METHODS

An IRB-approved single institution prospective phase II clinical trial of dose-escalated, hypofractionated RT as local control for STS was designed and completed planned accrual. Exclusion criteria included anti-cancer systemic therapy within the preceding two weeks. Patients underwent hypofractionated RT utilizing either CT-guided radiation (24, 50%) or MRI-guided radiation treatments (24, 50%). Data on patient characteristics, RT dose and fractionation, LC, toxicity, and overall survival (OS) was collected. The primary endpoint was local tumor control (stable, partial, or complete response according to RECIST) at 2-years after completion of radiation. Secondary endpoints were acute and late toxicity, rates of complete response, 5-year local tumor control, and progression-free and overall survival. Acute toxicity was graded on the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 scale during treatment and at 3 months following RT.

RESULTS

Forty-eight patients were enrolled, 17 with non-metastatic localized disease and 31 with metastatic disease. Median patient age was 64. Twenty-five men and 23 women were treated. Ninety-six total lesions were treated (36 lung, 7 extremity, 37 abdominopelvic, 16 other). Radiation dose per fraction ranged from 6-12 Gy for a total of 1-12 fractions (median dose was 52.5 Gy in 6 fractions. Median patient follow-up is 8.6 months (range 1 - 36 months). Six patients (13%) did not complete initial 3-month follow-up imaging. Of the 40 patients who have undergone 3-month follow up imaging, 32 (80%) had stable disease, 5 (12.5%) had partial response, 0 had complete response, and 3 (7.5%) had disease progression. Median PFS was 17.2 months at time of last follow up. Median OS was 12.9 months at time of last follow up. Twenty-five patients (52%) experienced an acute toxicity likely or possibly related to radiation. Three (6%) patients experienced CTACE grade 3 or greater treatment-related toxicity (pain, weakness, decreased range of motion, dermatitis).

CONCLUSION

In this initial report of a prospective, single-institution clinical trial of hypofractionated RT for STS not undergoing resection, we report low rates of acute grade 3 or greater toxicity and high rates of tumor response. We will continue to follow these patients to assess late toxicity and durability of tumor control.

Neoadjuvant Stereotactic MR-Guided Ablative Radiation Therapy (SMART) and Surgical Outcomes in Patients with Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

The benefit of neoadjuvant radiation therapy for patients undergoing surgery for pancreatic ductal adenocarcinoma (PDAC) remains unclear. Stereotactic MR-guided adaptive radiation therapy (SMART) treatment to ablative doses is a newer technique that is well tolerated and has increased local control in unresectable pancreatic cancer. For resectable pancreatic cancer, neoadjuvant SMART has the potential to decrease local recurrence risk and positive margin rates. However, there is concern for perioperative risks associated with ablative dose treatments. We report the efficacy and safety of surgical resection in patients who have received neoadjuvant SMART at our institution.

MATERIALS/METHODS

We conducted a retrospective analysis of all consecutive patients diagnosed with PDAC who had noted vascular involvement of the celiac axis, superior mesenteric, and/or portal vessels between January 2016 and December 2022 at a single, high-volume, academic institution. Perioperative events were defined according to the Clavien-Dindo classification. The Kaplan Meier method was applied to estimate disease free survival (DFS) and overall survival (OS).

RESULTS

Seventeen patients with PDAC and vessel involvement at time of diagnosis who received SMART were included. Median follow-up time was 14.3 months; all patients underwent surgery, at a median time after radiation of 28 days (range: 15 - 90). Median length of postoperative stay was 7 days (range: 3 - 15). Five patients (29%) underwent vascular resection. Fifteen patients (88%) achieved R0 resection, with two R1 resections noted at the SMA and pancreatic neck respectively. Seven patients (41%) had adverse events attributable to surgery, with the majority being defined as abscess or infection (n = 5; 29%). One (6%) Clavien-Dindo grade III or higher toxicity was observed - a cortical cerebrovascular event following surgery. No major bleeding events requiring surgical intervention were noted. At time of event censorship, there were no observable locoregional failures. The median DFS and OS were not reached; however, 1-year DFS and OS were 62% and 87%, respectively.

CONCLUSION

Neoadjuvant SMART appears to be safe, with low rates of surgical complications and promising outcomes. Further identification of patients for this approach requires additional investigation.

Full aperture backscatter diagnostics for characterization of laser plasma instabilities at the extreme light infrastructure (ELI) beamlines

We report on the commissioning of a full aperture backscatter diagnostics station for the kilojoule, nanosecond high repetition rate L4n laser operating at a wavelength of 527 nm at the Extreme Light Infrastructure (ELI) - Beamlines, Dolni Brezany, Czech Republic. Light scattered back from laser-plasma interaction into the cone of the final focusing lens is captured and split into different channels to measure the signatures of laser plasma instabilities from stimulated Brillouin scattering, stimulated Raman scattering, and two plasmon decay with respect to back scattered energy, its spectrum, and its temporal profile. The performance was confirmed in a commissioning experiment with more than 800 shots at laser intensities ranging from 0.5 × 1013 to 1.1 × 1015 W cm-2. These diagnostics are permanently installed at ELI Beamlines, and can be used to understand the details of laser-plasma interactions in experiments with kJ and 527 nm light. The large number of shots that can be collected in an experimental campaign will allow us to study the details of the laser-plasma interaction with a high level of confidence.

Case report: Rhabdomyolysis in children in acute and chronic disease-a challenging condition in pediatric emergency medicine

Rhabdomyolysis is a challenging condition in pediatric emergency departments (PED): It ranges from asymptomatic illness with isolated elevation of creatine kinase (CK) levels to a life-threatening condition associated with extreme elevations in CK, electrolyte imbalances, circulatory failure (CF), acute kidney injury (AKI), and multi-organ disease. Most common causes of rhabdomyolysis are viral myositis and trauma, hereditary metabolic myopathies must be considered when facing rhabdomyolysis in early childhood. We report two cases of severe rhabdomyolysis with CF in our PED, thereby summarizing first-line management of rhabdomyolysis.

Impact of atrial flow regulator implantation on survival in patients with heart failure with reduced and preserved ejection fraction: a post-hoc analysis of the PRELIEVE study

Purpose

This analysis aims to assess the theoretical impact of atrial flow regulator implantation on mortality by comparing the observed survival rate with the median predicted probability for one-year survival.

Methods

The prospective, multicentre, open-label, non-randomised PRELIEVE study assessed the safety and efficacy of the atrial flow regulator in patients with symptomatic HFrEF (left ventricular ejection fraction (LVEF) ≥15% and &lt;40%) or HFpEF (LVEF ≥40% and &lt;70%) and elevated PCWP (≥15mmHg at rest or ≥25mmHg during exercise). In this analysis, after the first 60 patients completed twelve months of follow-up, the theoretical impact of atrial flow regulator implantation on survival was assessed by comparing the observed mortality rate with the median predicted probability for one-year mortality. Each subject's risk of mortality was predicted from individual baseline data using the Meta-Analysis Global Group in Chronic HF (MAGGIC) prognostic model.

Results

A total of 87 patients had undergone successful device implantation for the treatment of HFrEF (53%) and HFpEF (47%). Sixty patients had a complete twelve-month follow-up. The median follow-up was 351 days (interquartile range [IQR] 202–370). A total of six (7%) patients died during follow-up (8.6 deaths per 100 patient-years; 95% confidence interval [CI] 2.7 to 15.5), all of which had HFrEF. The median predicted mortality rate for the overall study population was 12.2 deaths per 100 patient-years (95% CI 10.2 to 14.7). While the observed mortality rate (0 deaths per 100 patient-years) was significantly lower than the median predicted mortality rate (9.3 deaths per 100 patient-years; 95% CI 8.4 to 11.1) in patients with HFpEF (−9.3 deaths per 100 patient-years; 95% CI −11.1 to −8.4), there was no difference in patients with HFrEF (−3.6 deaths per 100 patient-years; 95% CI −9.5 to 3.0) (Figure 1). Four deaths were HF-related deaths (5.7 HF-related deaths per 100 patient-years; 95% CI 1.4 to 11.9; 10.8 HF-related deaths per 100 patient-years; 95% CI 2.5 to 23.1 in the HFrEF subgroup).

Conclusion

In patients with HFpEF, the mortality rate following atrial flow regulator implantation was lower than the predicted mortality rate. These findings need to be confirmed by larger randomised, controlled trials.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Occlutech International AB

Comparison of the 2010 and 2020 World Health Organization guidelines on physical activity in patients with percutaneous coronary interventions early after hospital discharge

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Swiss heart foundation

Background

Physical activity (PA) is inversely associated with mortality and adverse outcome in patients with cardiovascular disease, and can be objectively measured by accelerometry. In 2020, the World Health Organization (WHO) has updated their recommendations on PA for adults including those with chronic conditions, omitting the 10 min bout criterion.[1] The aim of this study was to determine the proportions of cardiac patients immediately after hospital discharge from percutaneous coronary interventions (PCI) who fulfil the old [2] and updated WHO PA criteria, and compare the results with established step-based cut-off values.

Methods

Patients after PCI for acute or chronic coronary syndrome with a maximal age of 80 and eligible for ambulatory cardiac rehabilitation were recruited for this observational single centre study. They were provided with a wrist-worn tri-axial accelerometer without display that recorded movement data starting from the day following hospital discharge for the subsequent 18 days. Acceleration data was analysed with the widely used free GGIR package. The proportions of patients fulfilling recommendations for moderate to vigorous PA (MVPA) were determined according to the 2010 and 2020 WHO guidelines as well as 7,500 [3] and 10,000 steps.[4]

Results

159 patients (41%) participated in this study. Data from 135 patients (85%), who had at least 7 days of ≥12 h wear-time were included in the analyses. Their median age was 62 (1st quartile 56, 3rd quartile 68), 22 (16%) were women, and 15 and 120 patients had a CCS and ACS, respectively. Their median wear time was 18 (16, 18) days. 102 (75.6%) had at least 30 min of MVPA on an average day and hence fulfilled the 2020 WHO guidelines. When MVPA was determined using the 2010 WHO guidelines, which only counted MVPA of bouts of at least 10 min, only 23 patients (17.8%) achieved at least 30 min of MVPA on an average day (Figure 1). 67.4% of our patients achieved ≥7,500 steps/d and 71 patients (52.6%) performed ≥10,000 steps/d.

Conclusion

In cardiac patients early after PCI most of the MVPA was accumulated in bouts shorter than 10 min. Applying the 2010 and 2020 WHO PA criteria to objectively measured PA led to a fourfold discrepancy. The 7,500 step cut-off corresponded with the 2020 WHO recommendations. Since achievement of intensity- or step-based cut-offs is greatly dependent on device type, wearing location, data sampling and analysis, it is currently poorly defined and not suited for patient classification and counselling. The clinical implication of this observation will be assessed in a cardiovascular outcome analysis.

CrMnFeCoNi high entropy alloys with carbon and nitrogen: mechanical properties, wear and corrosion resistance

The use of interstitial elements has been a key factor for the development of different kinds of steels. However, this aspect has been little explored in the field of high entropy alloys (HEAs). In this investigation, the effect of carbon and nitrogen in a near-equiatomic CrMnFeCoNi HEA is studied, analyzing their impact on the microstructure, and mechanical properties from 77K to 673K, as well as wear, and corrosion resistance. Carbon and nitrogen are part of the FCC solid solution and contribute to the formation of precipitates. An increase in the yield and ultimate tensile strength accompanied with a decrease in the ductility are the main effects of C and N. The impact toughness of the interstitial-free material is higher than that of C and C+N alloyed systems. Compared to CrNi and CrMn austenitic steels, the wear resistance of the alloys at room temperature is rather low. The surface corrosion resistance of HEAs is comparable to austenitic steels; nevertheless HEAs are more susceptible to pitting in chloride containing solutions.

High-repetition rate solid target delivery system for PW-class laser-matter interaction at ELI Beamlines

L3-HAPLS (High-repetition-rate Advanced Petawatt Laser System) at ELI (Extreme Light Infrastructure) Beamlines currently delivers 0.45 PW pulses (12 J in 27 fs) at 3.3 Hz repetition rate. A fresh target surface for every shot was placed at the laser focus using an in-house tape target system designed to withstand large laser intensities and energies. It has been tested for different material thicknesses (25 and 7.6 µm), while L3-HAPLS delivered laser shots for energies ranging from 1 to 12 J. A technical description of the tape target system is given. The device can be used in diverse geometries needed for laser-matter interaction studies by providing an ≈300° free angle of view on the target in the equatorial plane. We show experimental data demonstrating the shot-to-shot stability of the device. An x-ray crystal spherical spectrometer was set up to measure the Kα yield stability, while a GHz H-field probe was used to check the shot-to-shot electromagnetic pulse generation. Finally, we discuss short and mid-term future improvements of the tape target system for efficient user operation.

Treatment of intraoperative hypotension with cafedrine/theodrenaline versus ephedrine : A prospective, national, multicenter, non-interventional study-the HYPOTENS trial

BACKGROUND

Sympathomimetic drugs are a therapeutic cornerstone for the management of hypotensive states like intraoperative hypotension (IOH). While cafedrine/theodrenaline (C/T) is widely used in Germany to restore blood pressure in patients with IOH, more research is required to compare its effectiveness with alternatives such as ephedrine (E) that are more commonly available internationally.

METHODS

HYPOTENS (NCT02893241, DRKS00010740) was a prospective, national, multicenter, open-label, two-armed, non-interventional study that compared C/T with E for treatment of IOH. We describe a prospectively defined cohort of patients ≥50 years old with comorbidities undergoing general anesthesia induced with propofol and fentanyl. Primary objectives were to examine treatment precision, rapidity of onset and the ability to restore blood pressure without relevant increases in heart rate. Secondary endpoints were treatment satisfaction and the number of required additional boluses or other accompanying measures.

RESULTS

A total of 1496 patients were included in the per protocol analysis. Overall, effective stabilization of blood pressure was achieved with both C/T and E. Post-hoc analysis showed that blood pressure increase from baseline was more pronounced with C/T. Fewer additional boluses or other accompanying measures were required in the C/T arm. The incidence of tachycardia was comparable between groups. Post-hoc analysis showed that E produced dose-dependent elevated heart rate values. By contrast, heart rate remained stable in patients treated with C/T. Physicians reported a higher level of treatment satisfaction with C/T, with a higher proportion of anesthetists rating treatment precision and rapidity of onset as good or very good when compared with E.

CONCLUSION

Neither drug was superior in restoring blood pressure levels; however, post-hoc analyses suggested that treatment is more goal-orientated and easier to control with C/T. Heart rate was shown to be more stable with C/T and fewer additional interventions were required to restore blood pressure, which could have contributed to the increased treatment satisfaction reported by anesthetists using C/T.

[Lung ultrasound in COVID-19]

Die medizinische Versorgung von Patienten, die im Zusammenhang mit der pandemischen Coronaviruserkrankung 2019 („coronavirus disease 2019“, COVID-19) erkrankt sind, stellt für die staatlichen Gesundheitssysteme weltweit eine große Herausforderung dar. Das Virus mit dem Namen „severe acute respiratory syndrome coronavirus 2“ (SARS-CoV-2) zeigt eine hohe Organspezifität zu den unteren Atemwegen. Da bislang weder eine wirksame Therapie noch Impfung gegen das Virus existieren, kommt der diagnostischen Früherkennung eine große Bedeutung zu. Durch den spezifischen Aspekt der überwiegend im peripheren Lungenparenchym beginnenden Infektion ist die Lungensonographie als bildgebende Diagnostikmethode geeignet, Verdachtsfälle bereits im Frühstadium der Erkrankung als solche zu identifizieren. Serielle Ultraschalluntersuchungen an Patienten mit bestätigter Infektion können bettseitig und zeitnah Veränderungen im betroffenen Lungengewebe nachweisen. Dieser Artikel fasst das diagnostische Potenzial der Lungensonographie im Hinblick auf Screening und therapeutische Entscheidungsfindung bei Patienten mit vermuteter oder bestätigter SARS-CoV-2-Pneumonie zusammen.

Instrument flight to the inner ear

Surgical robot systems can work beyond the limits of human perception, dexterity and scale making them inherently suitable for use in microsurgical procedures. However, despite extensive research, image-guided robotics applications for microsurgery have seen limited introduction into clinical care to date. Among others, challenges are geometric scale and haptic resolution at which the surgeon cannot sufficiently control a device outside the range of human faculties. Mechanisms are required to ascertain redundant control on process variables that ensure safety of the device, much like instrument-flight in avionics. Cochlear implantation surgery is a microsurgical procedure, in which specific tasks are at sub-millimetric scale and exceed reliable visuo-tactile feedback. Cochlear implantation is subject to intra- and inter-operative variations, leading to potentially inconsistent clinical and audiological outcomes for patients. The concept of robotic cochlear implantation aims to increase consistency of surgical outcomes such as preservation of residual hearing and reduce invasiveness of the procedure. We report successful image-guided, robotic CI in human. The robotic treatment model encompasses: computer-assisted surgery planning, precision stereotactic image-guidance, in-situ assessment of tissue properties and multipolar neuromonitoring (NM), all based on in vitro, in vivo and pilot data. The model is expandable to integrate additional robotic functionalities such as cochlear access and electrode insertion. Our results demonstrate the feasibility and possibilities of using robotic technology for microsurgery on the lateral skull base. It has the potential for benefit in other microsurgical domains for which there is no task-oriented, robotic technology available at present.

ADAM10 inhibition improves survival and augments cardiac function after myocardial infarction

Background and purpose

Following myocardial infarction (MI), adverse fibrotic remodeling with extensive deposition of extracellular matrix (ECM) components has substantial consequences for the contractility of the ventricle finally leading to terminal heart failure (HF). Recently, inhibition of ECM-remodeling enzymes is discussed as potential treatment option for HF, especially following MI. The metalloprotease ADAM10 plays a crucial role in the development of the cardiovascular system and HF patients show elevated serum levels of the ADAM10 substrates CXCL16 and FasL. However, the causal role of ADAM10 in cardiovascular diseases has not been investigated. Here we evaluate the so far unknown role of ADAM10 in heart failure and after MI.

Methods and results

Our study capitalized from human atrial tissue biopsies, a cardiomyocyte-specific ADAM10 knockout (ADAM10 KO) mouse model as well as pharmacological ADAM10 inhibition following MI. ADAM10 expression analysis revealed elevated protein levels in HF patients compared to non-failing hearts. Upon MI, ADAM10 KO and pharmacological ADAM10 inhibition (GI254023X) significantly improved overall survival, significantly enhanced cardiac function (fractional area shortening - FAS, ejection fraction - EF) and significantly reduced infarct sizes. Compared to the high potential angiotensin receptor neprilysin inhibitor (ARNi) LCZ696, ADAM10 inhibition and combined ADAM10i/LCZ696 treatment resulted in preservation of cardiac function that was superior to sole LCZ696 treatment. Mechanistically, this functional improvement was due to reduced shedding of the ADAM10 substrate Notch1, induction of angiogenesis and an ADAM10-dependend inactivation of the NLRP3 inflammasome

Conclusion

Our data suggest that ADAM10 targeting is highly efficient for improving post-infarction cardiac function. Due to its overexpression in heart tissue of HF patients, ADAM10 could be a potential molecular target to improve therapy after MI. In terms of overall survival and pathophysiological remodeling following MI, our data suggest a greater potential of the ADAM10i/LCZ696 combinatorial therapy than sole LCZ696 treatment.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): German Heart Foundation/ German Foundation of Heart Research

PLK2 is a novel regulator of osteopontin-driven fibrosis and diastolic dysfunction in permanent atrial fibrillation

Background and aim

Atrial fibrillation (AF) is frequently accompanied by cardiac fibrosis and diastolic heart failure. Due to the heterogeneous nature and complexity of fibrosis, the knowledge of the underlying pathomechanisms is limited. Thus, effective antifibrotic pharmacotherapy is missing. The objective of this study was to decipher the role of polo-like kinase 2 (PLK2) in the pathogenesis of cardiac fibrosis and left ventricular diastolic dysfunction. We put particular emphasis on the identification of profibrotic downstream targets of PLK2, which can serve as therapeutic targets.

Methods and results

This study was based on human atrial tissue biopsies and peripheral blood samples, a PLK2 knockout mouse model, a canine tachy-pacing model and specific pharmacological interventions on cardiac fibroblasts. In human atrial AF tissue samples, PLK2 was 50% downregulated by hypoxia-induced promoter methylation compared to sinus rhythm (SR) control. Confirmatory analysis of a canine tachy-pacing model showed PLK2 downregulation exclusively in the atria but not in the ventricles. Specific pharmacological inhibition as well as genetic deletion of PLK2 led to a striking myofibroblast phenotype. Discovery proteomics revealed that the global knockout of PLK2 resulted in de novo secretion of the inflammatory cytokine osteopontin (OPN) in cardiac fibroblasts and concomitant ventricular fibrosis in the PLK2 knockout mouse model. An ELISA analysis of peripheral blood samples of AF patients with electrophysiologically proven fibrosis, confirmed significantly increased OPN plasma concentrations compared to SR and non-fibrosis AF controls. Consequently, echocardiography on PLK2 KO mice revealed left ventricular diastolic dysfunction, tachycardia and fibrosis-typical surface ECG anomalies (PQ and QRS prolongation). Mechanistically, we identified the ERK1/2 signaling pathway as the molecular link between reduced expression of PLK2 and elevated osteopontin transcription. In a reverse translational attempt, we successfully tested the capability of 5-amino-salicylic acid (5-ASA) to inhibit osteopontin transcription and to reverse a TGF-β-induced myofibroblast phenotype in vitro. Currently the long-term administration of 5-ASA is tested in PLK2 knockout mice to evaluate the therapeutic potential to prevent cardiac fibrosis and diastolic heart failure development.

Conclusion and clinical impact

We identified PLK2 as an epigenetically regulated kinase involved in the pathophysiology of fibrosis in AF. PLK2 knockout mice can serve as a model of diastolic heart failure wherein OPN is a promising therapeutic target. Our results strengthen the current hypothesis that atrial fibrillation is not only an ion channel disease but a complex systemic disorder. Restoration of physiological PLK2 expression and blockade of osteopontin release with 5-ASA may constitute valuable new drug targets for the prevention and treatment of fibrosis and diastolic heart failure in AF.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Faculty of Medicine, Carl Gustav Carus, Dresden, “MeDDrive Start” Grant

Transesophageal Echocardiography - Dysphagia Risk in Acute Stroke (TEDRAS): a prospective, blind, randomized and controlled clinical trial

BACKGROUND AND PURPOSE

Dysphagia is common in acute stroke and leads to worse overall outcome. Transesophageal echocardiography (TEE) is used in the diagnostic evaluation of stroke with regard to its etiology and is a known cause of postoperative dysphagia in cardiac surgery. The prevalence of dysphagia in acute stroke patients undergoing TEE remains unknown. The aim of the Transesophageal Echocardiography - Dysphagia Risk in Acute Stroke (TEDRAS) study was to assess the influence of TEE on swallowing among patients who have experienced acute stroke.

METHODS

The TEDRAS study was a prospective, blind, randomized, controlled trial that included two groups of patients with acute stroke. Simple unrestricted randomization was performed, and examiners were blinded to each other's results. Swallowing was tested using flexible endoscopic evaluation of swallowing (FEES) at three different time points in the intervention group (24 h before, immediately after and 24 h after TEE) and in the control group (FEES on three consecutive days and TEE earliest after the third FEES). Validated scales were used to assess dysphagia severity for all time points as primary outcome measures.

RESULTS

A total of 34 patients were randomized: 19 to the intervention group and 15 to the control group. The key findings of the repeated-measures between-group comparisons were significant increases in the intervention group for the following dysphagia measures: (1) secretion severity score (immediately after TEE: P < 0.001; 24 h after TEE: P < 0.001) and (2) Penetration-Aspiration Scale score for saliva (immediately after TEE: P < 0.001; 24 h after TEE: P = 0.007), for small (immediately after TEE: P = 0.009) and large liquid boli (immediately after TEE: P = 0.009; 24 h after TEE: P = 0.025).

CONCLUSION

The results indicate a negative influence of TEE on swallowing in acute stroke patients for at least 24 hours.

[Peripheral truncal blocks-Overview and assessment]

By implementation of sonography for regional anesthesia, truncal blocks became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety and helps to avoid complications during needle placement. Additionally, complex punctures are possible that were associated with higher risk using landmarks alone. Next to the blocking of specific nerve structures, interfascial and compartment blocks have also become established, whereby the visualization of individual nerves and plexus structures is not of relevance. The present review article describes published and clinically established puncture techniques with respect to the indications and procedures. The clinical value is reported according to the scientific evidence and the analgesic profile. Moreover, the authors explain potential risks, complications and dosing of local anesthetic agents.

SAT0342 INNATE LYMPHOID CELLS ARE PREDICTORS OF DISEASE PROGRESSION IN SYSTEMIC SCLEROSIS: A 3-YEARS FOLLOW-UP STUDY

Background:

Activation of the immune system is a characteristic feature of SSc. Numerous studies have suggested that type 2 are key drivers of progressive fibrosis. Recently, innate lymphoid cells (ILC) are emerging as an important cellular source of type 2 cytokines triggering fibrotic tissue remodeling independently of the adaptive immune system. Increased levels of ILC2 were found in patients with SSc. However, the contributive role of ILC2 in pathogenesis of SSc is not completely understood.

Objectives:

We aim in our 3 years observational study to evaluate the predictive role of ILC2 in SSc patients.

Methods:

We conducted an observational retrospective study on 52 patients with SSc fulfilling the 2013 ACR/EULAR classification criteria. Yearly clinical, laboratory and investigational data according to EUSTAR recommendations were collected. Blood samples collected between 15.09.2014 and 15.01.2015 were analyzed by flow cytometry and ILC2 counts were measured. The predictive value of ILC2 during a 3-year follow-up was analyzed using SPSS 21.0.

Results:

52 patients were included in the study, 78% female, 63% limited cutaneous SSc with a mean follow-up time of 2.85 ± 1.28 years. At baseline we have shown that circulating ILC2s are significantly increased compared to gender and age-matched healthy controls. Increased numbers of ILC2s significantly correlated with worsening of mRSS calculated by five point increase in mRSS or 25% increase from baseline (p < 0.001; 95% CI 1.39 – 3.26). ILC2 counts also correlated with 5% decrease of diffusion capacity of carbon monoxide (DLCO) during the follow-up time (p < 0.0001; 95% CI 1.83 – 3.49). Worsening of forced vital capacity (FVC) assessed as 5% decrease over 2 years was also significantly correlated with an increased number of ILC2s (p < 0.0001; 95% CI 1.27 – 3.04). In contrast, we did not find any correlation regarding increase in pulmonary arterial pressure assessed by echocardiography. Although new appearance of digital ulcers could not be predicted by ILC2 counts, increased numbers of ILC2s were correlated with digital ulcers at follow-up.

Conclusion:

Here, we provide first evidence for a role of ILC2s as potential prognostic marker of disease progression in SSc.

Disclosure of Interests:

Alina Soare: None declared, Stefanie Weber: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

OP0141 HIGH DIMENSIONAL ANALYSIS REVEAL A NETWORK OF CERTAIN TRANSCRIPTION FACTORS THAT LINK VASCULOPATHY AND ORGAN FIBROSIS IN SYSTEMIC SCLEROSIS

Background:

Since vascular manifestations such as Raynaud’s phenomenon often precede the onset of other clinical manifestations of systemic sclerosis (SSc), the identification of pathways linking vasculopathy to organ fibrosis might thus provide important insights into early disease mechanisms and allow early targeted intervention for both fibrotic and vascular events.

Objectives:

In this study we performed high dimensional (HD) analyses to identify mediators that link vasculopathy to organ fibrosis.

Methods:

HD techniques including RNA-seq, ChIP-seq, ATAC-seq and FISH-seq have been performed to identify mediators in vessels and fibrotic lesions of human skin samples of SSc patients and healthy volunteers. In addition, murine skin and lung tissue samples were analyzed by multi-channel immunofluorescence (IF) and confocal laser scanning microscopy. Microvascular endothelial cells, smooth muscle cells and fibroblasts have been further processed to address their functional attributes with regard to their proliferative, migratory and chemotactic capacity. In vivo models and ex vivomouse fetal metatarsal assays were performed to study fibrotic and angiogenic processes.

Results:

Bioinformatic HD analyses revealed the ETS transcription factor PU.1 as molecular checkpoint of a network of factors that drive matrix production and fibrotic imprinting in SSc. Within this network ATF3 was significantly upregulated in fibroblasts of skin biopsies of SSc patients and of various organs of fibrosis models. ATF3 deficiency ameliorated fibrosis in various mouse models. Notably, ATF3 was significantly upregulated in vascular cells of fibrotic tissues of SSc patients. Multi-channel IF and confocal laser scanning microscopy of skin and lung biopsies of SSc patients revealed an increased expression of ATF3 especially in microvascular endothelial cells and smooth muscle cells. ATF3 overexpression in smooth muscle cells led to an extensively enhanced proliferation and increased migratory capacity whereas endothelial cells showed a SSc-like phenotype with reduced proliferation and migration. After ATF3 overexpression, tube formation capacity was completely altered as assessed by cumulative tube length, tube numbers and capillary sprouting. To investigate vessel outgrowth from a different perspective, we used theex vivofetal mouse metatarsal assay. ATF3 knockout mice showed a completely altered angiogenic response as assessed by tube length, number of branches and number junctions compared to wildtype controls.

Conclusion:

We identified PU.1 and ATF3 as key factors in disturbed vasculature and endogenous activated fibroblasts suggesting this axis as a potential therapeutic target intervening both fibrotic and vascular manifestations.

Disclosure of Interests:

Charles Gwellem Anchang: None declared, Bettina Matalobos Lawaree: None declared, Stefanie Weber: None declared, Simon Rauber: None declared, Thomas Wohlfahrt: None declared, Markus Luber: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

SAT0354 TYPE 3 INNATE LYMPHOID CELLS ARE KEY DRIVERS OF PSORIATIC ARTHRITIS

Background:

Psoriasis (PsO) and psoriatic arthritis (PsA) are two types of chronic inflammatory diseases that share a similar cytokines profile. About 30% of PsO patients also develop a joint involvement, but the underlying mechanism is still unclear. Innate lymphoid cells (ILC) and specifically the type 3 ILCs (ILC3s) have raised increasing interest as possible player in the pathogenesis of both diseases, as they produce the pathological key cytokine IL-17A.

Objectives:

We addressed the contribution of ILC3s to the pathogenesis of PsO and PsA in patients as well as murinein vivomodels.

Methods:

130 patients satisfying the Classification Criteria for Psoriatic Arthritis (CASPAR), 40 patients with PsO and 35 healthy volunteers were enrolled in the study. Information regarding clinical features, laboratory parameters were collected and psoriasis area severity index (PASI), disease activity score 28 (DAS28), disease activity in psoriatic arthritis (DAPSA), minimal disease activity score (MDA) were calculated. Magnetic resonance imaging (MRI) and high-resolution peripheral CT (HR-pQCT) were taken and PsA MRI score (PsAMRIS) was assessed. Flow cytometric analysis was performed and IFNγ-producing ILC1s, IL-4/IL-5-producing ILC2s and IL-17/IL-22-producing ILC3s were identified among ILCs. Multivariate linear regression and Receiver-Operating Characteristic (ROC) Curve analysis was performed using the IBM SPSS Statistics software. Different in vivo models were used to assess functional implications of ILCs at different time points of the disease. Joint inflammation was assessed through MRI and H&E staining of ankle areas. Peripheral blood was obtained from mice of each group and flow cytometry analysis was performed. High dimensional analyses including RNA-seq was performed to identify phenotypic characteristics of ILCs implemented into the pathogenesis of the disease.

Results:

Total number of circulating ILCs were increased in PsA patients compared to PsO and healthy controls (p<0,001). Linear regression analyses of the relationship between disease activity and circulating ILCs counts showed strongest correlation between ILC3s counts and DAPSA score. ILC3s counts also correlated with imaging signs of inflammation such as enthesitis, synovitis, erosions and/or ostoeproliferation as assessed by MRI and HR-pQCT. Musculoskeletal inflammation in mice was predominantly associated with p19 expression and IL-23R-signaling as assessed by RNA-seq. These effects were also accompanied by a strong upregulation of IL-17-producing lymphocytes within the inflamed joint niche with a dominant presence of ILC3s. Multi-channel immunofluorescence and confocal laser scanning microscopy revealed not only upregulation of ILC3 induced IL-17 production within the synovial membrane but also in peri-articular areas of the inflamed joints.

Conclusion:

ILC3s not only correlate with various facets of PsA manifestations but also functionally contribute to synovitis and enthesitis suggesting them as interesting target for upcoming treatment strategies in the near future.

Disclosure of Interests:

Maria Gabriella Raimondo Grant/research support from: Celgene, Partner Fellowship, Simon Rauber: None declared, Markus Luber: None declared, Aleix Rius Rigau: None declared, Stefanie Weber: None declared, Charles Gwellem Anchang: None declared, Rahul Agarwal: None declared, Alina Soare: None declared, Michael Sticherling Grant/research support from: Novartis, Consultant of: Advisory boards Abbvie, Celgene, Janssen Cilag, Lilly, Pfizer, MSD, Novartis, Amgen, Leo, Sanofi, UCB, Speakers bureau: Abbvie, Celgene, Janssen Cilag, Leo, MSD, Novartis, Pfizer, Jürgen Rech Consultant of: BMS, Celgene, Novartis, Roche, Chugai, Speakers bureau: AbbVie, Biogen, BMS, Celgene, MSD, Novartis, Roche, Chugai, Pfizer, Lilly, Arnd Kleyer Consultant of: Lilly, Gilead, Novartis,Abbvie, Speakers bureau: Novartis, Lilly, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

SAT0302 INNATE LYMPHOID CELLS INDUCE A FIBROTIC PHENOTYPE OF FIBROBLASTS

Background:

Fibrotic diseases are characterized by excessive extracellular matrix production as a result of immune-mediated permanent fibroblast activation. Innate lymphoid cells type II (ILC2) are an only recently discovered cell type involved in barrier integrity and tissue homeostasis. There is upcoming evidence that ILC2s play a central role in mediating fibrotic diseases.

Objectives:

The aim of the study was to further elucidate the role of ILC2s in fibrotic tissue remodeling and fibroblast activation.

Methods:

Skin biopsies of patients with systemic sclerosis (SSc) or sclerodermatous chronic graft versus host disease (scGvHD) as well as lung biopsies of patients with idiopathic pulmonary fibrosis (IPF) were analyzed by immunofluorescence (IF) staining. Single cell RNA-sequencing (scRNA-seq) was performed on ILCs from fibrotic skin and lung of bleomycin-challenged mice. Further characterization of ILC2 phenotypes in fibrosis models was done by flow cytometry.In vitroculture of fibroblasts and ILC2s was used to study cellular interaction and fibrotic activation. Quantitative realtime-PCR, western blot, IF staining and ELISA were used as readouts.

Results:

Two different subtypes of ILC2s were found in skin of SSc and scGvHD patients as well as in lungs of IPF patients with one subpopulation being particularly increased in fibrotic tissue. Single cell RNA-sequencing confirmed the existence of two major populations of ILC2s in experimental fibrosis. One subtype showed features of immature ILC2 progenitors and was actively recruited from the bone marrow during fibrotic tissue remodeling. The other ILC2 subset was highly activated and expressed pro-fibrotic cytokines. These profibrotic ILC2s directly interacted with fibroblasts in a cell contact dependent manner. Semaphorin 4A (SEMA4A) expressed by ILC2s bound to Plexin D1 (PLXND1) on fibroblasts. This interaction resulted into fibrotic imprinting with high expression levels of the transcription factor PU.1 which was recently described as central regulator of the pro-fibrotic gene expression program (Wohlfahrt et al. 2019). Signaling through Jagged 1 (JAG1) and Notch receptor 2 (NOTCH2) was identified as a second mechanism of interaction between fibroblasts and ILC2s. JAG1 expressed by fibroblasts activated NOTCH2 signaling in ILC2s which emphazised the secretion of pro-fibrotic cytokines.

Conclusion:

We identified a bidirectional interaction between ILCs and fibroblasts incorporating a vicious circle of fibrotic tissue remodelling. As ILCs are still not accessible as therapeutic targets these results might contribute to the development of new strategies for anti-fibrotic therapies.

References:

[1]Wohlfahrt, Thomas, Simon Rauber, Steffen Uebe, Markus Luber, Alina Soare, Arif Ekici, Stefanie Weber, Alexandru-Emil Matei, Chih-Wei Chen, Christiane Maier, Emmanuel Karouzakis, Hans P. Kiener, Elena Pachera, Clara Dees, Christian Beyer, Christoph Daniel, Kolja Gelse, Andreas E. Kremer, Elisabeth Naschberger, Michael Stürzl, Falk Butter, Michael Sticherling, Susetta Finotto, Alexander Kreuter, Mark H. Kaplan, Astrid Jüngel, Steffen Gay, Stephen L. Nutt, David W. Boykin, Gregory M. K. Poon, Oliver Distler, Georg Schett, Jörg H. W. Distler, and Andreas Ramming. 2019. ‘PU.1 controls fibroblast polarization and tissue fibrosis’,Nature, 566: 344-49.

Disclosure of Interests:

Stefanie Weber: None declared, Charles Gwellem Anchang: None declared, Simon Rauber: None declared, Markus Luber: None declared, Maria Gabriella Raimondo Grant/research support from: Celgene, Partner Fellowship, Yuko Ariza Employee of: Ono Pharmaceutical Co., Ltd., Aleix Rius Rigau: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

AB0150 ADAPTOR PROTEINS ACTIVATE FIBROBLASTS IN SYSTEMIC SCLEROSIS

Background:

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by microangiopathy and fibrosis. In physiological wound healing, fibroblasts are transiently activated for tissue repair. In contrast, fibroblasts are persistently activated during fibrosis and thus resulted in progressive matrix deposition and tissue remodeling. However, the pathogenesis of the fibrotic process is not fully understood.

Objectives:

We aimed to identify molecules that play a role in chronically activated fibroblasts.

Methods:

To identify molecules specifically upregulated in human fibrotic fibroblasts, RNA-sequencing was performed. Identified adaptor proteins were further validated in skin biopsy samples of patients with limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), and evaluated correlation between expression levels and clinical parameters. Respective overexpression and siRNA knockdown were further addressedin vitro. Functional effects were assessed by qPCR, hydroxyproline, proliferation and migration assays. Mouse models of systemic sclerosis were used to functionally validate adaptor proteinsin vivo.

Results:

We identified adaptor proteins as significantly upregulated molecules in chronically active fibroblasts of skin biopsy samples from SSc patients compared to fibroblasts from healthy controls. Expression levels were correlated with the modified Rodnan skin score in the skin of SSc patients. We observed higher expression levels also in the mouse model of topoisomerase I induced skin fibrosis. This result was also observed in bleomycin induced lung fibrosis model suggesting important functions of adaptor proteins during fibrotic tissue remodeling across different organs. Fibroblast-specific knockout resulted into significantly attenuated bleomycin-induced fibrosis. Upon bleomycin challenge, hydroxyproline content was diminished in mice with genetic deficiency of adaptor proteins. In addition, COL1A1, COL1A2 and Lum mRNAs and also the number of myofibroblasts were significantly lower in knockout mice compared to wild type mice.In vitro, knockdown of adaptor proteins resulted into a significant alteration of the migratory potential of fibroblasts.

Conclusion:

Our results demonstrate that adaptor proteins play an essential role in the pathogenesis of systemic sclerosis. Understanding the molecular mechanism of adaptor proteins may lead to a novel therapeutic intervention in human SSc and related disorders.

Disclosure of Interests:

Yuko Ariza Employee of: Ono Pharmaceutical Co., Ltd., Stefanie Weber: None declared, Nils Neise: None declared, Alexander Kreuter: None declared, Georg Schett Speakers bureau: AbbVie, BMS, Celgene, Janssen, Eli Lilly, Novartis, Roche and UCB, Jörg Distler Grant/research support from: Boehringer Ingelheim, Consultant of: Boehringer Ingelheim, Paid instructor for: Boehringer Ingelheim, Speakers bureau: Boehringer Ingelheim, Andreas Ramming Grant/research support from: Pfizer, Novartis, Consultant of: Boehringer Ingelheim, Novartis, Gilead, Pfizer, Speakers bureau: Boehringer Ingelheim, Roche, Janssen

Absorption and opacity threshold for a thin foil in a strong circularly polarized laser field

We show that a commonly accepted transparency threshold for a thin foil in a strong circularly polarized normally incident laser pulse needs a refinement. We present an analytical model that correctly accounts for laser absorption. The refined threshold is determined not solely by the laser amplitude, but by other parameters that are equally or even more important. Our predictions are in perfect agreement with particle-in-cell simulations. The refined criterion is crucial for configuring laser plasma experiments in the high-field domain. In addition, an opaque foil steepens the pulse front, which can be important for numerous applications.

Laser-based synchrotron X-ray radiation experimental scaling

We review the results obtained in several experimental campaigns with the INRS high-power laser system and determine the X-ray emission scaling from synchrotron radiation produced during laser wakefield acceleration (LWFA) of electrons. The physical processes affecting the generation of intense and stable X-ray beams during the propagation phase of the high-intensity ultrashort pulse in the gas jet target are discussed. We successfully produced stable propagation in the gas jet target of a relativistic laser pulse through self-guiding on length larger than the dephasing and depletion lengths, generating very intense beams of hard X-rays with up to 200 TW on target. The experimental scaling law obtained for the photon yield in the 10-40 keV range is presented and the level of X-ray emission at the 1 PW laser peak power level, now available at several laser facilities, is estimated.

Mobile health technologies for the management of systemic lupus erythematosus: a systematic review

OBJECTIVE

We aimed to perform a standardized review of available mobile health (mHealth) applications (apps) for systemic lupus erythematosus (SLE) and to conduct a systematic review of the literature on mHealth technologies in SLE.

METHODS

Google Play and AppStore in the United States of America were queried and the quality of eligible mHealth apps was assessed using the Mobile App Rating Scale (MARS). Web of Science, EMBASE, Medline, and Cochrane databases were systematically searched from inception through June 2019.

RESULTS

Of 324 mHealth apps found, 20 were eligible for inclusion; 10 focused on education, 7 offered tools to track patient-reported symptoms, 5 included interactive online communities, and 1 enabled emoji sharing. The reviewed apps scored poorly on the MARS quality scale with a mean score 2.3 (0.6) out of 5. Of 1147 studies identified in the literature review, 21 were eligible for inclusion; 11 studies (52.4%) focused on the development and use of mHealth for providing patient information, while only 2 (9.5%) were randomized trials of mHealth interventions.

CONCLUSIONS

Although there is growing interest in the development of mHealth technologies to support SLE patients, currently available tools are of poor quality and limited functionality, and the literature examining this area is sparse.

Infections caused by extended-spectrum β-lactamase-producing Enterobacterales after rectal colonization with ESBL-producing Escherichia coli or Klebsiella pneumoniae

OBJECTIVES

Infections as a result of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) are considered infections with a high public health burden. In this study, we aimed to identify incidences of and risk factors for healthcare-associated infections (HAIs) after rectal colonization with ESBL-producing Escherichia coli (ESBL-EC) or Klebsiella pneumoniae (ESBL-KP).

METHODS

This prospective cohort study was performed in 2014 and 2015. Patients colonized with ESBL-EC or ESBL-KP were monitored for subsequent HAI with ESBL-E and other pathogens. In the case of an ESBL-E infection, rectal and clinical isolates were compared using pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing (WGS) for ESBL-KP isolates. Proportional hazard models were applied to identify risk factors for HAIs, and to analyse competing risks.

RESULTS

Among all patients admitted to the hospital during the study period, 13.6% were rectally screened for third-generation cephalosporin-resistant Enterobacterales (3GCREB). A total of 2386 rectal carriers of ESBL-EC and 585 of ESBL-KP were included in the study. Incidence density (ID) for HAI with ESBL-E was 2.74 per 1000 patient days at risk (95% confidence interval (CI) 2.16-3.43) among carriers of ESBL-EC, while it was 4.44 per 1000 patient days at risk (95% CI 3.17-6.04) among carriers of ESBL-KP. In contrast, ID for HAI with other pathogens was 4.36 per 1000 patient days at risk (95% CI 3.62-5.21) among carriers of ESBL-EC, and 5.00 per 1000 patient days at risk (95% CI 3.64-6.69) among carriers of ESBL-KP. Cox proportional hazard regression analyses identified colonization with ESBL-KP (HR = 1.58, 95% CI 1.068-2.325) compared with ESBL-EC as independent risk factor for HAI with ESBL-E. The results were consistent over all competing risk analyses.

CONCLUSIONS

Clinicians should be aware of the increased risk of ESBL-E infections among patients colonized with ESBL-KP compared with ESBL-EC that might be caused by underlying diseases, higher pathogenicity of ESBL-KP and other factors.

Nonlinear dynamics of laser-generated ion-plasma gratings: A unified description

Laser-generated plasma gratings are dynamic optical elements for the manipulation of coherent light at high intensities, beyond the damage threshold of solid-state-based materials. Their formation, evolution, and final collapse require a detailed understanding. In this paper, we present a model to explain the nonlinear dynamics of high-amplitude plasma gratings in the spatially periodic ponderomotive potential generated by two identical counterpropagating lasers. Both fluid and kinetic aspects of the grating dynamics are analyzed. It is shown that the adiabatic electron compression plays a crucial role as the electron pressure may reflect the ions from the grating and induce the grating to break in an X-type manner. A single parameter is found to determine the behavior of the grating and distinguish three fundamentally different regimes for the ion dynamics: completely reflecting, partially reflecting or passing, and crossing. Criteria for saturation and lifetime of the grating as well as the effect of finite ion temperature are presented.

[Navigated liver surgery : Current state and importance in the future]

The preoperative computer-assisted resection planning is the basis for every navigation. Thanks to modern algorithms, the prerequisites have been created to carry out a virtual resection planning and a risk analysis. Thus, individual segment resections can be precisely planned in any conceivable combination. The transfer of planning information and resection suggestions to the operating theater is still problematic. The so-called stereotactic liver navigation supports the exact intraoperative implementation of the planned resection strategy and provides the surgeon with real-time three-dimensional information on resection margins and critical structures during the resection. This is made possible by a surgical navigation system that measures the position of surgical instruments and then presents them together with the preoperative surgical planning data. Although surgical navigation systems have been indispensable in neurosurgery and spinal surgery for many years, these procedures have not yet become established as standard in liver surgery. This is mainly due to the technical challenge of navigating a moving organ. As the liver is constantly moving and deforming during surgery due to respiration and surgical manipulation, the surgical navigation system must be able to measure these alterations in order to adapt the preoperative navigation data to the current situation. Despite these advances, further developments are required until navigated liver resection enters clinical routine; however, it is already clear that laparoscopic liver surgery and robotic surgery will benefit most from navigation technology.

Optimization of off-axis electron holography performed with femtosecond electron pulses

We report on electron holography experiments performed with femtosecond electron pulses in an ultrafast coherent Transmission Electron Microscope based on a laser-driven cold field emission gun. We first discuss the experimental requirements related to the long acquisition times imposed by the low emission/probe current available in these instruments. The experimental parameters are first optimized and electron holograms are then acquired in vacuum and on a nano-object showing that useful physical properties can nevertheless be extracted from the hologram phase in pulsed condition. Finally, we show that the acquisition of short exposure time holograms assembled in a stack, combined with a computer-assisted shift compensation of usual instabilities encountered in holography, such as beam and biprism wire instabilities, can yield electron holograms acquired with a much better contrast paving the way to ultrafast time-resolved electron holography.

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.

Accuracy assessment of a potential clinical use of navigation-guided intra-operative liver metastasis brachytherapy-a planning study

For patients with inoperable liver metastases, intra-operative liver high dose-rate brachytherapy (HDR-BT) is a promising technology enabling delivery of a high radiation dose to the tumor, while sparing healthy tissue. Liver brachytherapy has been described in the literature as safe and effective for the treatment of primary or secondary hepatic malignancies. It is preferred over other ablative techniques for lesions that are either larger than 4 cm or located in close proximity to large vessels or the common bile duct. In contrast to external beam radiation techniques, organ movements do not affect the size of the irradiated volume in intra-operative HDR-BT and new technical solutions exist to support image guidance for intra-operative HDR-BT. We have retrospectively analyzed anonymized CT datasets of 5 patients who underwent open liver surgery (resection and/or ablation) in order to test whether the accuracy of a new image-guidance method specifically adapted for intra-operative HDR-BT is high enough to use it in similar situations and whether patients could potentially benefit from navigation-guided intra-operative needle placement for liver HDR-BT.

Zoonotic origin and transmission of Middle East respiratory syndrome coronavirus in the UAE

Since the emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, there have been a number of clusters of human-to-human transmission. These cases of human-to-human transmission involve close contact and have occurred primarily in healthcare settings, and they are suspected to result from repeated zoonotic introductions. In this study, we sequenced whole MERS-CoV genomes directly from respiratory samples collected from 23 confirmed MERS cases in the United Arab Emirates (UAE). These samples included cases from three nosocomial and three household clusters. The sequences were analysed for changes and relatedness with regard to the collected epidemiological data and other available MERS-CoV genomic data. Sequence analysis supports the epidemiological data within the clusters, and further, suggests that these clusters emerged independently. To understand how and when these clusters emerged, respiratory samples were taken from dromedary camels, a known host of MERS-CoV, in the same geographic regions as the human clusters. Middle East respiratory syndrome coronavirus genomes from six virus-positive animals were sequenced, and these genomes were nearly identical to those found in human patients from corresponding regions. These data demonstrate a genetic link for each of these clusters to a camel and support the hypothesis that human MERS-CoV diversity results from multiple zoonotic introductions.

Abstract P3-08-14: Prediction of distant recurrence in low risk early breast cancer by RT-qPCR based subtyping using MammaTyper®

Background:

Estrogen receptor (ER/ESR1), progesterone receptor (PR/PGR) and epidermal growth factor receptor 2 (HER2/ERBB2) are routinely assessed by immunohistochemistry (IHC) during workup of breast cancer samples. The routine use of Ki67 (MKI67) IHC assessment in the context of breast cancer subtyping, however, remains controversial, due to poor reproducibility and lack of standardization.

The MammaTyper® test is an in-vitro diagnostic (IVD) test which measures the expression status of the four breast cancer biomarkers ERBB2, ESR1, PGR and MKI67 on the mRNA level via reverse transcription-quantitative PCR (RT-qPCR) and has demonstrated a high degree of reproducibility in the assessment of the four markers.

In this retrospective analysis we assessed the prognostic power of molecular subtyping by MammaTyper® in archived samples from low risk early breast cancers treated with adjuvant endocrine therapy only.

Methods:

ER+/HER2- (according to initial diagnosis) FFPE breast cancer samples from patients treated with adjuvant endocrine therapy only were obtained from 6 different centers. Tumor cellularity was assessed by H&E staining and RNA was extracted from samples with a tumor cell content of ≥20% using a bead-based RNA purification kit (RNXtract®). Total RNA was then used as input for MammaTyper® RT-qPCR. Expression values were classified as positive or negative for each marker based on predefined cutoff values. Tumor subtypes were assigned to each sample based on the combination of binary (pos/neg) single marker expression status according the St Gallen surrogate subtype definition. Distant disease free survival of Luminal A-like samples vs. samples with other subtypes was assessed by Kaplan Meier analysis and Cox regression using SAS version 9.4.

Results:

The final analysis included 319 samples with sufficient tumor cellularity and RNA content for reliable analysis. The rate of distant recurrence in the analyzed set was 8.5%. Median follow up was 7.8 years. The MammaTyper® test called 60% (192) of samples as Luminal-A-like (4.7% (9) distant events), 37% (119) as Luminal B-like (HER2 negative) (13.4% (16) distant events), 1.3% (4) as Triple negative (ductal) (25% (1) distant events), 0.6% (2) as “not defined according to St Gallen” (ESR1-/PGR+) (50% (1) distant events) and 0.6% (2) as Luminal B-like (HER2 positive) (no distant events).

When comparing Luminal A-like samples with the samples of the other subtypes in survival analysis, Luminal A-like samples had a significantly better distant disease free survival when assessing samples from patients with pN0 status (278) (p=0.0177, HR=0.344 (95% CI 0.137-0.866), pN1 status (0-3 affected nodes) (314) (p=0.0153, HR=0.374 (95% CI 0.163-0.855) as well as for all samples (p=0.0032, HR=0.319 (95% CI 0.143-0.711).

Conclusion:

Determination of HER2, ER, PR and Ki67 mRNA levels allows molecular subtyping according to the St Gallen surrogate subtype definition. Low risk of distant recurrence could be confirmed for the MammaTyper® Luminal A-like samples suggesting that for this patient group endocrine treatment alone may be sufficient. The high degree of standardization of mRNA measurement may drive the use of the Ki67/MKI67 biomarker in routine breast cancer pathology.

Citation Format: Laible M, Hartmann K, Gürtler C, Anzeneder T, Weber S, Keller T, Sahin U. Prediction of distant recurrence in low risk early breast cancer by RT-qPCR based subtyping using MammaTyper® [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 P3-08-14.

[Pioneering surgical innovations in Germany : Part 1: generation of medical evidence]

BACKGROUND

In recent years research which conforms to evidence-based medicine (EBM) has been required even in surgery. Prospective, randomized studies are carried out in order to provide justification for the benefits of new procedures.

OBJECTIVE

The acquisition of special features in surgery with respect to the application of EBM.

MATERIAL AND METHODS

The investigation period selected was from1933 to 2013; therefore, all disciplines within the German Society of Surgery were questioned on the achievement of revolutionary innovations. The investigation was carried out utilizing personal interviews and a questionnaire. Only novel methods which were developed in Germany were considered. The survey was completed by carrying out research in database files.

RESULTS

During the past 80 years 15 pioneering innovations have been published in surgical research, although the prerequisites of EBM were only partly met. They appear to be based on the lowest level of evidence as these methods were mostly published as case reports or case series in journals with a low impact factor.

DISCUSSION

In general, innovative surgical procedures through top level research are still being published in the form of case reports or case series. This allows a rapid distribution of research results to the surgical community. Controlled studies still do not represent an alternative for the introduction of pioneering surgical innovations.

A Linear Programming Approach to Limited Angle 3D Reconstruction from DSA Projections

Objectives: We investigate the feasibility of binary-valued 3D tomographic reconstruction using only a small number of projections acquired over a limited range of angles.

Methods: Regularization of this strongly ill-posed problem is achieved by (i) confining the reconstruction to binary vessel/non-vessel decisions, and (ii) by minimizing a global functional involving a smoothness prior.

Results: Our approach successfully reconstructs volumetric vessel structures from three projections taken within 90°. The percentage of reconstructed voxels differing from ground truth is below 1%.

Conclusion: We demonstrate that for particular applications – like Digital Subtraction Angiography – 3D reconstructions are possible where conventional methods must fail, due to a severely limited imaging geometry. This could play an important role for dose reduction and 3D reconstruction using non-conventional technical setups.

Bonner Venenstudie der Deutschen Gesellschaft für Phlebologie

Ziel: Die Bonner Venenstudie zur Frage der Häufigkeit und Ausprägung von chronischen Venenkrankheiten in der städtischen und ländlichen deutschen Wohnbevölkerung im Alter von 18-79 Jahren fand zwischen dem 13. 11. 2000 und 15. 3. 2002 statt. Es nahmen insgesamt 3072 Probanden teil, die Response-Proportion lag insgesamt bei 59%. Ergebnisse: Eine Beinschwellung in der Anamnese trat bei jedem 6. Mann (16,2%) und bei nahezu jeder 2. Frau (42,1%) auf. Eine kurz zurückliegende ein- oder beidseitige Beinschwellung in den letzten vier Wochen gab jeder 6. Teilnehmer an. Dies entspricht 14,8% (7,9% der Männer, 20,2% der Frauen). Für Gefäßerkrankungen typische Beinbeschwerden innerhalb der letzten vier Wochen gab insgesamt jeder 2. der Probanden (56,4%) an. Bei der Beurteilung der klinischen Ausprägung gemäß der CEAP-Klassifikation fällt auf, dass lediglich 9,6% der Probanden keinerlei Venenveränderungen aufweisen. Bei 59% bestehen isoliert Teleangiektasien oder retikuläre Venen, bei 14,3% Krampfadern (C2) ohne weitere Zeichen einer chronischen venösen Insuffizienz. Auffällig ist, dass bei 13,4% ein prätibiales Ödem im Rahmen von Venenveränderungen zum Untersuchungszeitpunkt vorlag. Demgegenüber liegt die Zahl der fortgeschrittenen Zeichen der chronischen venösen Insuffizienz bei 3,3%. Die Häufigkeit des floriden oder abgeheilten Ulcus cruris lag bei 0,7%. Schlussfolgerungen: Jeder 6. Mann und jede 5. Frau hat somit chronische Veneninsuffizienz (C3–C6). Die Zahlen zeigen, dass Venenkrankheiten insgesamt nach wie vor eine hohe Prävalenz aufweisen, dass aber die schweren Ausprägungen der chronischen venösen Insuffizienz in den vergangenen 20 Jahren zurückgegangen sind.

Development of a high brightness ultrafast Transmission Electron Microscope based on a laser-driven cold field emission source

We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond laser pulses which are tightly focused by optical components integrated inside a cold field emission source close to the cathode. The properties of the electron probe (brightness, angular current density, stability) are quantitatively determined. The measured brightness is the largest reported so far for UTEMs. Examples of imaging, diffraction and spectroscopy using ultrashort electron pulses are given. Finally, the potential of this instrument is illustrated by performing electron holography in the off-axis configuration using ultrashort electron pulses.