EADV Task Force Pruritus White Paper on chronic pruritus and chronic prurigo: Current challenges and future solutions

Chronic pruritus (CP) is frequent in general medicine and the most common complaint in general dermatology. The prevalence of CP is expected to rise in the future due to the ageing population. The clinical presentation, underlying aetiology and treatment strategy of CP are heterogeneous. Also, individual treatment aims and physical, psychic and economic burdens of patients might vary. Chronic prurigo (CPG) is the most severe disease in the chronic pruritus spectrum, being associated with long-standing scratch-induced skin lesions and a therapy refractory itch-scratch-cycle. It is thus important to raise disease awareness for CP and CPG in the general public and among decision-makers in the health system. Further, there is a need to support a rational clinical framework to optimize both diagnostics and therapeutics. Currently, there is still a shortcoming regarding approved therapies and understanding CP/CPG as severe medical conditions. Therefore, the EADV Task Force Pruritus decided to publish this white paper based on several consensus meetings. The group consented on the following goals: (a) ensure that CP is recognized as a serious condition, (b) increase public awareness and understanding of CP and CPG as chronic and burdensome diseases that can greatly affect a person's quality of life, (c) clarify that in most cases CP and CPG are non-communicable and not caused by a psychiatric disease, (d) improve the support and treatment given to patients with CP to help them manage their disease and (e) publicize existing therapies including current guidelines. We aim to point to necessary improvements in access and quality of care directed to decision-makers in health policy, among payers and administrations as well as in practical care.

Automated quantification of vacuole fusion and lipophagy in Saccharomyces cerevisiae from fluorescence and cryo-soft X-ray microscopy data using deep learning

During starvation in the yeast Saccharomyces cerevisiae vacuolar vesicles fuse and lipid droplets (LDs) can become internalized into the vacuole in an autophagic process named lipophagy. There is a lack of tools to quantitatively assess starvation-induced vacuole fusion and lipophagy in intact cells with high resolution and throughput. Here, we combine soft X-ray tomography (SXT) with fluorescence microscopy and use a deep-learning computational approach to visualize and quantify these processes in yeast. We focus on yeast homologs of mammalian NPC1 (NPC intracellular cholesterol transporter 1; Ncr1 in yeast) and NPC2 proteins, whose dysfunction leads to Niemann Pick type C (NPC) disease in humans. We developed a convolutional neural network (CNN) model which classifies fully fused versus partially fused vacuoles based on fluorescence images of stained cells. This CNN, named Deep Yeast Fusion Network (DYFNet), revealed that cells lacking Ncr1 (ncr1∆ cells) or Npc2 (npc2∆ cells) have a reduced capacity for vacuole fusion. Using a second CNN model, we implemented a pipeline named LipoSeg to perform automated instance segmentation of LDs and vacuoles from high-resolution reconstructions of X-ray tomograms. From that, we obtained 3D renderings of LDs inside and outside of the vacuole in a fully automated manner and additionally measured droplet volume, number, and distribution. We find that ncr1∆ and npc2∆ cells could ingest LDs into vacuoles normally but showed compromised degradation of LDs and accumulation of lipid vesicles inside vacuoles. Our new method is versatile and allows for analysis of vacuole fusion, droplet size and lipophagy in intact cells.Abbreviations: BODIPY493/503: 4,4-difluoro-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-Indacene; BPS: bathophenanthrolinedisulfonic acid disodium salt hydrate; CNN: convolutional neural network; DHE; dehydroergosterol; npc2∆, yeast deficient in Npc2; DSC, Dice similarity coefficient; EM, electron microscopy; EVs, extracellular vesicles; FIB-SEM, focused ion beam milling-scanning electron microscopy; FM 4-64, N-(3-triethylammoniumpropyl)-4-(6-[4-{diethylamino} phenyl] hexatrienyl)-pyridinium dibromide; LDs, lipid droplets; Ncr1, yeast homolog of human NPC1 protein; ncr1∆, yeast deficient in Ncr1; NPC, Niemann Pick type C; NPC2, Niemann Pick type C homolog; OD600, optical density at 600 nm; ReLU, rectifier linear unit; PPV, positive predictive value; NPV, negative predictive value; MCC, Matthews correlation coefficient; SXT, soft X-ray tomography; UV, ultraviolet; YPD, yeast extract peptone dextrose.

Kinetic modelling of sterol transport between plasma membrane and endo-lysosomes based on quantitative fluorescence and X-ray imaging data

Niemann Pick type C1 and C2 (NPC1 and NPC2) are two sterol-binding proteins which, together, orchestrate cholesterol transport through late endosomes and lysosomes (LE/LYSs). NPC2 can facilitate sterol exchange between model membranes severalfold, but how this is connected to its function in cells is poorly understood. Using fluorescent analogs of cholesterol and quantitative fluorescence microscopy, we have recently measured the transport kinetics of sterol between plasma membrane (PM), recycling endosomes (REs) and LE/LYSs in control and NPC2 deficient fibroblasts. Here, we use kinetic modeling of this data to determine rate constants for sterol transport between intracellular compartments. Our model predicts that sterol is trapped in intraluminal vesicles (ILVs) of LE/LYSs in the absence of NPC2, causing delayed sterol export from LE/LYSs in NPC2 deficient fibroblasts. Using soft X-ray tomography, we confirm, that LE/LYSs of NPC2 deficient cells but not of control cells contain enlarged, carbon-rich intraluminal vesicular structures, supporting our model prediction of lipid accumulation in ILVs. By including sterol export via exocytosis of ILVs as exosomes and by release of vesicles-ectosomes-from the PM, we can reconcile measured sterol efflux kinetics and show that both pathways can be reciprocally regulated by the intraluminal sterol transfer activity of NPC2 inside LE/LYSs. Our results thereby connect the in vitro function of NPC2 as sterol transfer protein between membranes with its in vivo function.

3D surface reconstruction of cellular cryo-soft X-ray microscopy tomograms using semisupervised deep learning

Cryo-soft X-ray tomography (cryo-SXT) is a powerful method to investigate the ultrastructure of cells, offering resolution in the tens of nanometer range and strong contrast for membranous structures without requiring labeling or chemical fixation. The short acquisition time and the relatively large field of view leads to fast acquisition of large amounts of tomographic image data. Segmentation of these data into accessible features is a necessary step in gaining biologically relevant information from cryo-soft X-ray tomograms. However, manual image segmentation still requires several orders of magnitude more time than data acquisition. To address this challenge, we have here developed an end-to-end automated 3D segmentation pipeline based on semisupervised deep learning. Our approach is suitable for high-throughput analysis of large amounts of tomographic data, while being robust when faced with limited manual annotations and variations in the tomographic conditions. We validate our approach by extracting three-dimensional information on cellular ultrastructure and by quantifying nanoscopic morphological parameters of filopodia in mammalian cells.

Improvement in compliance of ships' ballast water discharges during commissioning tests

The number of ships installing ballast water management systems (BWMS) has risen steeply since the Ballast Water Management Convention entered into force. Since June 2022, biological testing is required during commissioning to verify compliance with the Convention. Data from 676 tests (from 2019 to 2022) show substantial improvement over time: the failure rate decreased from ~20 % to ~6 %. Notably, nearly all failures occurred in the largest size class of organisms (≥50 μm). Interestingly, proxy measurements suggest that high concentrations of living organisms in uptake water did not cause the failures. Also, failures determined using "indicative" analysis (here, adenosine triphosphate, ATP) were typically not confirmed by "detailed" analysis (microscopy), suggesting that ATP limits are over-precautionary. Finally, discharges containing high levels of Total Residual Oxidants (TRO) decreased over time. These data highlight the need for ongoing testing-focusing at least on organisms ≥50 μm-to minimize environmental risks from organisms transported in ships' ballast water.

Spectromicroscopy of Nanoscale Materials in the Tender X-Ray Regime Enabled by a High Efficient Multilayer-Based Grating Monochromator

The combination of near edge X-ray absorption spectroscopy with nanoscale X-ray imaging is a powerful analytical tool for many applications in energy technologies, catalysis, which are critical to combat climate change, as well as microelectronics and life science. Materials from these scientific areas often contain key elements, such as Si, P, S, Y, Zr, Nb, and Mo as well as lanthanides, whose X-ray absorption edges lie in the so-called tender photon energy range 1.5-5.0 keV. Neither conventional grazing incidence grating nor crystal monochromators have high transmission in this energy range, thereby yielding the tender photon energy gap. To close this gap, a monochromator setup based on a multilayer coated blazed plane grating and plane mirror is devised. The measurements show that this novel concept improves the photon flux in the tender X-ray regime by two-orders-of-magnitude enabling previously unattainable laboratory and synchrotron-based studies. This setup is applied to perform nanoscale spectromicroscopy studies. The high photon flux provides sufficient sensitivity to obtain the electronic structure of Mo in platinum-free MoNi₄ nanoparticles for electrochemical energy conversion. Additionally, it is shown that the chemical bonding of nano-structures in integrated circuits can be distinguished by the electronic configuration at the Si-K edge.

Exploring Stakeholder Requirements to Enable the Research and Development of Artificial Intelligence Algorithms in a Hospital-Based Generic Infrastructure: Protocol for a Multistep Mixed Methods Study

BACKGROUND

In recent years, research and developments in advancing artificial intelligence (AI) in health care and medicine have increased. High expectations surround the use of AI technologies, such as improvements for diagnosis and increases in the quality of care with reductions in health care costs. The successful development and testing of new AI algorithms require large amounts of high-quality data. Academic hospitals could provide the data needed for AI development, but granting legal, controlled, and regulated access to these data for developers and researchers is difficult. Therefore, the German Federal Ministry of Health supports the Protected Artificial Intelligence Innovation Environment for Patient-Oriented Digital Health Solutions for Developing, Testing, and Evidence-Based Evaluation of Clinical Value (pAItient) project, aiming to install the AI Innovation Environment at the Heidelberg University Hospital in Germany. The AI Innovation Environment was designed as a proof-of-concept extension of the already existing Medical Data Integration Center. It will establish a process to support every step of developing and testing AI-based technologies.

OBJECTIVE

The first part of the pAItient project, as presented in this research protocol, aims to explore stakeholders' requirements for developing AI in partnership with an academic hospital and granting AI experts access to anonymized personal health data.

METHODS

We planned a multistep mixed methods approach. In the first step, researchers and employees from stakeholder organizations were invited to participate in semistructured interviews. In the following step, questionnaires were developed based on the participants' answers and distributed among the stakeholders' organizations to quantify qualitative findings and discover important aspects that were not mentioned by the interviewees. The questionnaires will be analyzed descriptively. In addition, patients and physicians were interviewed as well. No survey questionnaires were developed for this second group of participants. The study was approved by the Ethics Committee of the Heidelberg University Hospital (approval number: S-241/2021).

RESULTS

Data collection concluded in summer 2022. Data analysis is planned to start in fall 2022. We plan to publish the results in winter 2022 to 2023.

CONCLUSIONS

The results of our study will help in shaping the AI Innovation Environment at our academic hospital according to stakeholder requirements. With this approach, in turn, we aim to shape an AI environment that is effective and is deemed acceptable by all parties.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/42208.

[Tumor predisposition syndromes and nephroblastoma : Early diagnosis with imaging]

CLINICAL/METHODICAL ISSUE

The Beckwith-Wiedemann spectrum (BWSp) as well as the WT1-related syndromes, Denys-Drash syndrome (DDS) and WAGR spectrum (Wilms tumor, Aniridia, genitourinary anomalies and a range of developmental delays) are tumor predisposition syndromes (TPS) of Wilms tumor (WT). Patients with associated TPS are at higher risk of developing chronic kidney disease and bilateral and metachronous tumors as well as nephrogenic rests.

STANDARD RADIOLOGICAL METHODS

Standard imaging diagnostics for WT include renal ultrasound and magnetic resonance imaging (MRI). In the current renal tumor studies Umbrella SIOP-RTSG 2016 and Randomet 2017, thoracic computed tomography (CT) is also recommended as standard. Positron emission tomography (PET)-CT and whole-body MRI, on the other hand, are not part of routine diagnostics.

METHODOLOGICAL INNOVATIONS

In recent publications, renal ultrasound is recommended every 3 months until the age of 7 years in cases of clinical suspicion or molecularly proven TPS.

PERFORMANCE

Patients with TPS and regular renal ultrasounds have smaller tumor volumes and lower tumor stages at WT diagnosis than patients without such a screening. This allows a reduction of therapy intensity and facilitates the performance of nephron sparing surgery, which is prognostically relevant especially in bilateral WT.

ACHIEVEMENTS

Early diagnosis of WT in the context of TPS ensures the greatest possible preservation of healthy and functional renal tissue. Standardized screening by regular renal ultrasounds should therefore be firmly established in clinical practice.

PRACTICAL RECOMMENDATIONS

The initial diagnosis of TPS is clinical and requires a skilled and attentive examiner in the presence of sometimes subtle clinical manifestations, especially in the case of BWSp. Clinical diagnosis should be followed by genetic testing, which should then be followed by sonographic screening.

Surgomics: personalized prediction of morbidity, mortality and long-term outcome in surgery using machine learning on multimodal data

BACKGROUND

Personalized medicine requires the integration and analysis of vast amounts of patient data to realize individualized care. With Surgomics, we aim to facilitate personalized therapy recommendations in surgery by integration of intraoperative surgical data and their analysis with machine learning methods to leverage the potential of this data in analogy to Radiomics and Genomics.

METHODS

We defined Surgomics as the entirety of surgomic features that are process characteristics of a surgical procedure automatically derived from multimodal intraoperative data to quantify processes in the operating room. In a multidisciplinary team we discussed potential data sources like endoscopic videos, vital sign monitoring, medical devices and instruments and respective surgomic features. Subsequently, an online questionnaire was sent to experts from surgery and (computer) science at multiple centers for rating the features' clinical relevance and technical feasibility.

RESULTS

In total, 52 surgomic features were identified and assigned to eight feature categories. Based on the expert survey (n = 66 participants) the feature category with the highest clinical relevance as rated by surgeons was "surgical skill and quality of performance" for morbidity and mortality (9.0 ± 1.3 on a numerical rating scale from 1 to 10) as well as for long-term (oncological) outcome (8.2 ± 1.8). The feature category with the highest feasibility to be automatically extracted as rated by (computer) scientists was "Instrument" (8.5 ± 1.7). Among the surgomic features ranked as most relevant in their respective category were "intraoperative adverse events", "action performed with instruments", "vital sign monitoring", and "difficulty of surgery".

CONCLUSION

Surgomics is a promising concept for the analysis of intraoperative data. Surgomics may be used together with preoperative features from clinical data and Radiomics to predict postoperative morbidity, mortality and long-term outcome, as well as to provide tailored feedback for surgeons.

Exploring Stakeholder Requirements to enable research and development of AI algorithms in a hospital based generic infrastructure: Results of a Multi-step mixed-methods Study (Preprint)

BACKGROUND

Legal, controlled, and regulated access to high-quality data from academic hospitals currently poses a barrier to the development and testing of new artificial intelligence (AI) algorithms. To overcome this barrier, the German Federal Ministry of Health supports the "pAItient" (Protected Artificial Intelligence Innovation Environment for Patient Oriented Digital Health Solutions for developing, testing and evidence-based evaluation of clinical value) project, with the goal to establish an AI Innovation Environment at the Heidelberg University Hospital, Germany. It is designed as a proof-of-concept extension to the preexisting Medical Data Integration Center.

OBJECTIVE

The first part of the pAItient project aims to explore stakeholders' requirements for developing AI in partnership with an academic hospital and granting AI experts access to anonymized personal health data.

METHODS

We designed a multistep mixed methods approach. First, researchers and employees from stakeholder organizations were invited to participate in semistructured interviews. In the following step, questionnaires were developed based on the participants' answers and distributed among the stakeholders' organizations. In addition, patients and physicians were interviewed.

RESULTS

The identified requirements covered a wide range and were conflicting sometimes. Relevant patient requirements included adequate provision of necessary information for data use, clear medical objective of the research and development activities, trustworthiness of the organization collecting the patient data, and data should not be reidentifiable. Requirements of AI researchers and developers encompassed contact with clinical users, an acceptable user interface (UI) for shared data platforms, stable connection to the planned infrastructure, relevant use cases, and assistance in dealing with data privacy regulations. In a next step, a requirements model was developed, which depicts the identified requirements in different layers. This developed model will be used to communicate stakeholder requirements within the pAItient project consortium.

CONCLUSIONS

The study led to the identification of necessary requirements for the development, testing, and validation of AI applications within a hospital-based generic infrastructure. A requirements model was developed, which will inform the next steps in the development of an AI innovation environment at our institution. Results from our study replicate previous findings from other contexts and will add to the emerging discussion on the use of routine medical data for the development of AI applications.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/42208.

Estimation and Monitoring of Operating Room Utilization by a Distributed Streaming and Analytics Architecture Deployed at Heidelberg University Hospital's Medical Data Integration Center

Operating rooms are a major cost factor in a hospital's budget. Therefore, there is a need for process optimization related to the operating rooms (OR). However, the collection of key figures for process optimization is often done manually by medical staff. This can be erroneous, inaccurate, time consuming, and incomplete. Automated, data-driven approaches are intended to address these problems and help to get the most precise picture possible of what is happening within the OR. At Heidelberg University Hospital (UKHD), a distributed AI based streaming analytics architecture was set up and integrated into the Medical Data Integration Center (MeDIC). This architecture can process, store, and visualize heterogeneous data from different sources. Data from medical devices and the video stream of the wall mounted cameras of four integrated operating rooms are ingested into our system. Aggregated and analyzed in real-time computed key figures including OR state and utilization numbers are visualized in a dashboard for monitoring and decision support. Because of high data protection hurdles the proposed system, especially the video analytics, was trained and tested with statists and did not run during real procedures. Studies to evaluate and test the system during live surgeries are planned.

X-ray Fourier transform holography with beam shaping optical elements

Holography is a powerful method for achieving 3D images of objects. Extending this method to short wavelengths potentially offers significantly higher resolution than visible light holography. However, current X-ray holography setups employ nanoscale pinholes to form the reference wave. This approach is relatively inefficient and limited to very small sample size. Here, we propose a new setup for X-ray holography based on a binary diffractive optical element (DOE), which forms at the same time the object illumination and the reference wave. This optic is located separately from the sample plane, which permits investigation of larger sample areas. Using an extended test sample, we demonstrate a resolution of 90 nm (half-pitch) at an undulator beamline at BESSY II. The new holography setup can be directly transferred to free electron laser sources enabling time-resolved nanoscale imaging for ultra-fast processes.

Reflection on the proposed changes to dose quantities-an industrial perspective

In 2021, the ICRP initiated the revision of the general recommendations of the system of radiation protection, and part of it will focus on dose quantities. The recently published ICRP Publication 147 and ICRU Report 95 have described the extent of the proposed modifications and paved the way for the strategy to be adopted. These revisions would seek to simplify, improve the accuracy and extend the field of use of dose quantities. While the Radiological Protection Working Group of the World Nuclear Association recognises the notable improvement in the estimation of the protection quantities and the usefulness of such changes for the medical and research sector, the benefits of the proposed new system seem very limited for the nuclear industry and industries involving naturally occurring radioactive materials. The complexity associated with changing a long-standing and robust system and the risk incurred by the human factor seem unjustified, bearing in mind the likely cost.

Reflections on low-dose radiation, the misconceptions, reality and moving forward

Low dose radiation has been widely accepted by the radiation protection community as presenting a very low risk to human health, if any. Over-conservatism in optimisation principles and regulations have resulted in a disproportionate fear of radiation amongst the general public and government authorities alike, overlooking the great benefits nuclear science and techniques have brought to society as a whole. As such, the World Nuclear Association advocates for a recontextualisation of the radiation hazards with regards to low dose radiation, and a greater awareness as to the absence of any discernible effects associated with it.

POS0091 OFF-TARGET PROFILING OF JANUS KINASE (JAK) INHIBITORS IN RHEUMATOID ARTHRITIS: A COMPUTER-BASED APPROACH FOR DRUG SAFETY STUDIES AND REPURPOSING

Background:

The JAK inhibitors (JAKi’s) tofacitinib and baricitinib are new alternatives for treating rheumatoid arthritis. Safety concerns associated with JAKi’s, such as the increased risk for thrombosis and viral infections, have emerged worldwide. The underlying explanatory mechanisms remain unknown, suggesting the elevated risk is likely due to underlying confounding or an off-target binding effect. Computational approaches can explore the potential for a small molecule drug to interact with previously unknown biological targets and identify potential safety-related concerns, and open doors for potential drug repurposing.

Objectives:

To identify and characterize the off-target binding effects of baricitinib and tofacitinib, with a focus on targets related to thrombosis and viral infection

Methods:

Potential targets of baricitinib and tofacitinib were predicted using two neural-network-based systems (TIGER[1] and SPiDER[2]). Targets were considered relevant if they had (1) a SPiDER confidence with p<0.05, or (2) a TIGER score >1. Selected targets related to the outcome of interest were experimentally evaluated at Eurofins Cerep (France-Celle L’Evescault, www.eurofins.com) if commercial available. Compounds were tested at (1) single concentration (30 µM) with technical replicates, using radioligand or enzymatic assays, or (2) multiple concentrations (30 µM highest concentration; dilution factor in a log-scale) with technical replicates, using calcium flux or inhibition of [cAMP] assays. Observed activity of ≥50% inhibition or stimulation on the target was considered active, between 25 to 50% inhibition (or a dissociation constant [Kd] from 1 to 10 µM) was considered as moderate activity, and lower than 25% was considered inactive. Dose-response curve were performed on active and moderate targets for IC50 / EC50 (half maximal inhibitory / effective concentration) determination.

Results:

TIGER and SPiDER suggested a total of 99 off-target binding effects (baricitinib n=41; tofacitinib n=58), of which 17 targets had potential impact on thrombosis or viral infection (baricitinib n=5 and 4, respectively; tofacitinib n=5 and 3, respectively). Commercial testing was available on 11 targets (Adenosine Receptor A2A [AA2AR], Epidermal growth factor receptor, induclible NOS, PI3 Kinase (p110b/p85a), Phosphodiesterase 10A2 [PDE10A2] and Protein Kinase N2 [PKN2] for baricitinib; and Adenosine receptor A3, 15-Lipoxygenase [15-LO], PKN2, Transient receptor potential cation channel [TRPM6] and AA2AR for tofacitinib). Of these, 5 targets showed active or moderately active binding activity (baricitinib n=2; tofacitinib n=3), and were tested for dose-response curves. Test results confirmed ligand-binding activity with IC50 on nanomolar (PKN2), and micromolar ranges (PDE10A2 and TRPM6).

Conclusion:

The results suggest both baricitinib and tofacitinib are promiscuous binders with effects on several families. Although it may lead to side effects, off-target binding also represents a potential opportunity for drug repurposing. Besides on-target effects, both drugs are under clinical investigation for the treatment of COVID-19 due to off-target interactions. The proposed pharmacological off-target effects of those with active binding include attenuation of pulmonary vascular remodeling, anti-fibrotic and anti-psychotic activities (PDE10A2), modulation of viral response (PKN2), and hypomagnesaemia (TRPM6), which is involved in cardiovascular diseases. This study supports tofacitinib and baricitinib as candidates for drug repurposing (e.g., in COVID-19, Hepatitis C virus, and pulmonary hypertension). We did not identify active off-target interactions linked to thrombosis to explain the elevated risk observed in clinical practice. Further research is required to elucidate the underlying patient-specific factors (confounders) that could explain this safety concern.

References:

[1]Schneider P et al. Angew Chem Int Ed 2017;56:11520–4.

[2]Reker D et al. PNAS 2014;111:4067–72.

Disclosure of Interests:

None declared

Quantitative imaging of membrane contact sites for sterol transfer between endo-lysosomes and mitochondria in living cells

Mitochondria receive cholesterol from late endosomes and lysosomes (LE/LYSs) or from the plasma membrane for production of oxysterols and steroid hormones. This process depends on the endo-lysosomal sterol transfer protein Niemann Pick C2 (NPC2). Using the intrinsically fluorescent cholesterol analog, cholestatrienol, we directly observe sterol transport to mitochondria in fibroblasts upon treating NPC2 deficient human fibroblasts with NPC2 protein. Soft X-ray tomography reveals the ultrastructure of mitochondria and discloses close contact to endosome-like organelles. Using fluorescence microscopy, we localize endo-lysosomes containing NPC2 relative to mitochondria based on the Euclidian distance transform and use statistical inference to show that about 30% of such LE/LYSs are in contact to mitochondria in human fibroblasts. Using Markov Chain Monte Carlo image simulations, we show that interaction between both organelle types, a defining feature of membrane contact sites (MCSs) can give rise to the observed spatial organelle distribution. We devise a protocol to determine the surface fraction of endo-lysosomes in contact with mitochondria and show that this fraction does not depend on functional NPC1 or NPC2 proteins. Finally, we localize MCSs between LE/LYSs containing NPC2 and mitochondria in time-lapse image sequences and show that they either form transiently or remain stable for tens of seconds. Lasting MCSs between endo-lysosomes containing NPC2 and mitochondria move by slow anomalous sub-diffusion, providing location and time for sterol transport between both organelles. Our quantitative imaging strategy will be of high value for characterizing the dynamics and function of MCSs between various organelles in living cells.

Niemann Pick C2 protein enables cholesterol transfer from endo-lysosomes to the plasma membrane for efflux by shedding of extracellular vesicles

The Niemann-Pick C2 protein (NPC2) is a sterol transfer protein in the lumen of late endosomes and lysosomes (LE/LYSs). Absence of functional NPC2 leads to endo-lysosomal buildup of cholesterol and other lipids. How NPC2's known capacity to transport cholesterol between model membranes is linked to its function in living cells is not known. Using quantitative live-cell imaging combined with modeling of the efflux kinetics, we show that NPC2-deficient human fibroblasts can export the cholesterol analog dehydroergosterol (DHE) from LE/LYSs. Internalized NPC2 accelerated sterol efflux extensively, accompanied by reallocation of LE/LYSs containing fluorescent NPC2 and DHE to the cell periphery. Using quantitative fluorescence loss in photobleaching of TopFluor-cholesterol (TF-Chol), we estimate a residence time for a rapidly exchanging sterol pool in LE/LYSs localized in close proximity to the plasma membrane (PM), of less than one min and observed non-vesicular sterol exchange between LE/LYSs and the PM. Excess sterol was released from the PM by shedding of cholesterol-rich vesicles. The ultrastructure of such vesicles was analyzed by combined fluorescence and cryo soft X-ray tomography (SXT), revealing that they can contain lysosomal cargo and intraluminal vesicles. Treating cells with apoprotein A1 and with nuclear receptor liver X-receptor (LXR) agonists to upregulate expression of ABC transporters enhanced cholesterol efflux from the PM, at least partly by accelerating vesicle release. We conclude that NPC2 inside LE/LYSs facilitates non-vesicular sterol exchange with the PM for subsequent sterol efflux to acceptor proteins and for shedding of sterol-rich vesicles from the cell surface.

The burden in chronic prurigo: patients with chronic prurigo suffer more than patients with chronic pruritus on non-lesional skin: A comparative, retrospective, explorative statistical analysis of 4,484 patients in a real-world cohort

BACKGROUND

Chronic prurigo (CPG) is known as a high burdensome disease characterized by severe pruritus and multiple pruriginous lesions. Interestingly, the disease-specific burden is not well established and there are no data which compare the impact of CPG with chronic pruritus (CP) on non-lesional skin (CP-NL).

OBJECTIVES

To address this issue, we analysed datasets from 4484 patients with either CPG or CP-NL.

METHODS

Demographic medical data and additional information collected by validated patient reported outcome tools were analysed. The visual analogue scale and numerical rating scale (NRS) were used for assessing the pruritus intensity, the ItchyQoL for patients' quality of life, the Hospital Anxiety and Depression Scale and the Patient Needs Questionnaire' as a part of Patient Benefit Index for Pruritus for measuring the importance of 27 patient needs in terms of treatment goals. The Neuroderm questionnaire was used to assess the history of pruritus characteristics and the impact on sleep.

RESULTS

Patients with CPG suffered longer and with a higher intensity from pruritus [NRS worst the last 24 h, CPG 6.0 (4.0;8.0) vs. CP-NL 3.0 (5.0;7.0), P < 0.001]. In them, pruritus occurred more often and the whole day and night which led to more loss in sleeping hours [CPG 3.0 h (2.0;4.0) vs. CP-NL 2.0 h (1.0;4.0), P < 0.001]. Patients with CPG showed higher scores for depression [HADS-D, CPG 6.0 (3.0;10.0) vs. CP-NL 5.0 (2.0;8.0), P < 0.001], more impaired quality of life [ItchyQol; CPG: 72.6 (61.6;83.6) vs. CP-NL 59.4 (48.4;70.4), P < 0.001] and higher weighted needs in the predefined treatment goals.

DISCUSSION

Not only the presence of severe pruritus and pruriginous lesions but also sleep disorders and other mental symptoms may contribute to a higher burden in patients with CPG when compared with patients with CP-NL.

Central hemodynamic effects in patients with chronic coronary syndrome after long-term ivabradine therapy

Objectives

We sought to assess central hemodynamic effects in 23 patients (18 male, 5 female) with a resting heart rate (HR) of ≥70 beats per minute (bpm) and chronic coronary syndrome after long-term ivabradine therapy (6 months) by cardiac magnetic resonance (CMR).

Methods and results

In a cross-over design, all patients were treated with ivabradine (Iva, 7.5 mg bid) and placebo for 6 months each. CMR was performed three times (at baseline, after 6 and 12 months) to determine left ventricular (LV) function parameters, including end-diastolic and end-systolic volumes (EDVi, ESVi), stroke volume (SVi) and ejection fraction (EF) as well as volume-time curve (VTC) parameters, including peak ejection rate (PER), peak ejection time (PET), peak filling rate (PFR), peak filling time from ES (PFT), peak ejection rate normalized to EDV (PER/EDV) and peak filling rate normalized to EDV (PFR/EDV) for global LV function (systolic and diastolic) assessment. Flow measurements of the ascending aorta were performed with phase-contrast velocity imaging.

Treatment with Iva led to a HR reduction of 11.4 bpm (Iva 58.8±8.2 bpm vs placebo 70.2±8.3 bpm, p&lt;0.0001).There was no difference in LVEF (%) (Iva 57.4±11.2 vs placebo 53.0±10.9, p=0.18), EDVi or ESVi. SVi (ml/m2) remained comparatively unchanged after long-term treatment with Iva (Iva 40.6±9.6 vs placebo 35.7±8.8, p=0.08). VTC parameters reflecting systolic LV function (PER, PET) were unaffected by Iva, while both PFR and PFR/EDV were significantly increased (PFR/EDV (s-1) Iva 2.4±0.4 vs placebo 2.1±0.4, p=0.03). There was a trend to longer PFT during treatment with Iva, though not reaching statistical significance. Medium and maximum aortic flow were not affected by treatment with Iva, while mean velocity (cm/s) was significantly reduced (Iva 6.7±2.7 vs placebo 9.0±3.4, p=0.01). Aortic flow parameters were correlated to aortic distensibility (AD), as surrogate parameter for arterial stiffness. AD was significantly correlated to both aortic flow and flow velocity, whereby mean velocity showed the strongest correlation to AD (r=0.74 [0.61 to 0.83], p&lt;0.0001).

Conclusion

Systolic LV function was unaffected by treatment with Iva, while the filling during diastole was significantly improved. While medium and maximum aortic flow were not affected by Iva, mean velocity was significantly reduced. Aortic distensibility as surrogate parameter for arterial stiffness was significantly correlated to aortic mean velocity. This study confirms the underlying physiological principle of the If-current inhibitor Ivabradine.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): This work was supported by the Deutsche Herzstiftung (German Heart Foundation) (F/14/11 to F.C.) and the Deutsche Forschungsgemeinschaft (DFG KFO 196 to U.L., S.H.S and M.B. and SFB TTR 219, S-01 to M.B.). The Saarland University Medical Center has received an unrestricted grant from Servier (France).

Scanning acoustic microscopy investigation of weld lines in injection-molded parts manufactured from industrial thermoplastic polymer

Scanning acoustic microscopy (SAM) is used to characterize welds in a thermoplastic polymer (ABS) manufactured by injection-molding, particularly at the locations of weld-lines known to form as unavoidable significant defects. Acoustic micrographs obtained at 420 MHz clearly resolve the weld lines with morphological deformations and microelastic heterogenity. This is also where terahertz (THz) measurements, carried out in support of the SAM study, reveal enhanced birefringence corresponding to the location of these lines enabling verification of the SAM results. Rayleigh surface acoustic waves (RSAW), quantified by V(z) curves (with defocusing distance of 85 μm), are found to propagate slower in regions close to the weld lines than in regions distant from these lines. The discrepancy of about 100 m/s in the velocity of RSAW indicates a large variation in the micro-elastic properties between areas close to and distant from the weld lines. The spatial variations in velocity (V_R) of RSAWs indicate anisotropic propagation of the differently polarized ultrasonic waves.

Introducing the CSP Analyzer: A novel Machine Learning-based application for automated analysis of two-dimensional NMR spectra in NMR fragment-based screening

NMR-based screening, especially fragment-based drug discovery is a valuable approach in early-stage drug discovery. Monitoring fragment-binding in protein-detected 2D NMR experiments requires analysis of hundreds of spectra to detect chemical shift perturbations (CSPs) in the presence of ligands screened. Computational tools are available that simplify the tracking of CSPs in 2D NMR spectra. However, to the best of our knowledge, an efficient automated tool for the assessment and binning of multiple spectra for ligand binding has not yet been described. We present a novel and fast approach for analysis of multiple 2D HSQC spectra based on machine-learning-driven statistical discrimination. The CSP Analyzer features a C# frontend interfaced to a Python ML classifier. The software allows rapid evaluation of 2D screening data from large number of spectra, reducing user-introduced bias in the evaluation. The CSP Analyzer software package is available on GitHub https://github.com/rubbs14/CSP-Analyzer/releases/tag/v1.0 under the GPL license 3.0 and is free to use for academic and commercial uses.

Cells Undergo Major Changes in the Quantity of Cytoplasmic Organelles after Uptake of Gold Nanoparticles with Biologically Relevant Surface Coatings

Here, we use cryo soft X-ray tomography (cryo-SXT), which delivers 3D ultrastructural volumes of intact cells without chemical fixation or staining, to gain insight about nanoparticle uptake for nanomedicine. We initially used dendritic polyglycerol sulfate (dPGS) with potential diagnostic and therapeutic applications in inflammation. Although dPGS-coated gold nanoparticle (dPGS-AuNP) uptake followed a conventional endocytic/degradative pathway in human lung epithelial cell lines (A549), with cryo-SXT, we detected ∼5% of dPGS-AuNPs in the cytoplasm, a level undetectable by confocal light microscopy. We also observed ∼5% of dPGS-AuNPs in a rarely identified subcellular site, namely, lipid droplets, which are important for cellular energy metabolism. Finally, we also found substantial changes in the quantity of cytoplasmic organelles upon dPGS-AuNP uptake over the 1-6 h incubation period; the number of small vesicles and mitochondria significantly increased, and the number of multivesicular bodies and the number and volume of lipid droplets significantly decreased. Although nearly all organelle numbers at 6 h were still significantly different from controls, most appeared to be returning to normal levels. To test for generality, we also examined cells after uptake of gold nanoparticles coated with a different agent, polyethylenimine (PEI), used for nucleic acid delivery. PEI nanoparticles did not enter lipid droplets, but they induced similar, albeit less pronounced, changes in the quantity of cytoplasmic organelles. We confirmed these changes in organelle quantities for both nanoparticle coatings by confocal fluorescence microscopy. We suggest this cytoplasmic remodeling could reflect a more common cellular response to coated gold nanoparticle uptake.

[Is the discipline associated with self-confidence in handling rational antibiotic prescription? : Results from the MR2 study in German hospitals]

BACKGROUND

Besides public awareness and specialist knowledge and training of physicians, their self-confidence plays a key role for clinical decision-making in the respective area.

OBJECTIVE

This exploratory study investigated the influence of the discipline on differences in self-confidence in dealing with antibiotics and in the self-rated knowledge.

METHODS

In 2015 the multi-institutional reconnaissance of practice with multiresistant bacteria (MR2) questionnaire containing items on antibiotic prescription and multiresistant pathogens was sent out to 1061 physicians working in departments for internal medicine, general surgery, gynecology and obstetrics and urology. In 2017 a similar MR2 survey was sent to 1268 specialist and assistant physicians in anesthesiology in Germany. Besides demographic data 4 items on self-confidence in the use of antibiotic treatment and 11 items concerning self-rated knowledge about rational antibiotic therapy and multiresistant pathogens were included in the present analysis. Logistic regression analysis, the χ²-test and the Kruskal-Wallis test were used for statistical analysis of the influence of the discipline on these items.

RESULTS

The response rates were 43% (456 out of 1061) from the non-anesthetists and 56% (705 out of 1268) from the anesthetists. Of the non-anesthetists 44% and 57% of the anesthetists had had no advanced training on antibiotic stewardship during the year before the study. In the overall analysis anesthetists (mean±SD: 2.53±0.54) were significantly less self-confident about antibiotics than colleagues from other departments (internal medicine: 3.10±0.50, general surgery: 2.97±0.44, gynecology and obstetrics: 3.12±0.42 and urology: 3.15±0.44) in the unadjusted (all p<0.001) and adjusted comparison. The analysis of self-rated knowledge about rational antibiotic prescription showed similar results. Senior consultant status and advanced training in infectiology were significantly associated with self-confidence and self-rated knowledge about antibiotics.

CONCLUSION

Anesthetists showed significantly less self-confidence in dealing with antibiotics than colleagues from other disciplines. Advanced training on a rational prescription of antibiotics was associated with a greater self-confidence, so that the implementation of compulsory courses on rational antibiotic stewardship in the respective residency curriculum needs to be considered.

Risk detection in patients with obstructive sleep apnea syndrome based on cardiovascular time series analysis

Obstructive sleep apnea represents the most common form of sleep-disordered breathing and has a high prevalence in patients with cardiovascular disease. Disturbed sleep is a potential risk factor for cardiovascular disorders such as arterial hypertension, cardiac ischemia, sudden cardiac death, and stroke. In this study we investigated polysomnographic records and analyzed the ECG, plethysmogram, respiration and SpO2 time series during wakefulness (WK), NREM, and REM sleep stages applying variability and coupling analyses methods. We enrolled 55 patients with obstructive sleep apnea syndrome (OSAS) and 29 healthy control subjects (CON: 45.9±14.9 years, 21 male) in this study. OSAS patients were subdivided into a low- and high-risk group (LR: 50.8±14.1 years, n=29, 21 male; HR: 57.2±13.4 years, n=26, 19 male) based on the Apnea-Hypopnea Index (AHI) (CON: 0-5 AHI, LR: 5-15 AHI, HR: >15 AHI). We could demonstrate the presence of an altered autonomic function in OSAS patients, differing from healthy controls. This altered autonomic function was mainly based on heart rate-, respiratory-, SpO2- and plethysmogram variability and their couplings. The discriminant analysis showed that the optimal set consisting of two autonomic indices revealed a high classification power (ACC=86.7%, AUC=90.3%, SENS=89.5% and SPEC=84.6%) when comparing low-risk and high-risk OSAS patients during WK. These results were slightly improved when analyzing REM sleep stages. Based on these results it seems to be possible to perform optimal risk stratification for OSAS patients based on autonomic indices. Based on our findings it is possible to differentiate between high-risk OSAS patient and low-risk OSAS patient at an early stage and in a promising manner allowing to set up therapy strategies for those patients in an early stage.

The German version of the Critical-Care Pain Observation Tool for critically ill adults : A prospective validation study

BACKGROUND

The implementation of the Critical-Care Pain Observation tool (CPOT) in intensive care units (ICU) has been associated with more frequent pain assessments, a reduced number of complications, and improved administration of analgesics and sedatives. So far no German translation exists. Translating this tool into foreign languages requires further validation testing.

OBJECTIVE

The aim of this prospective observational validation study was to translate the original version of the CPOT according to scientific principles for translation and to establish the validity and reliability of the German translation of CPOT for critically ill adult patients.

MATERIAL AND METHODS

A total of 292 cardiac surgery patients from 2 ICUs of 2 German university teaching hospitals were included (114 patients at center 1 and 178 patients at center 2). Of the included patients 22.6% were female and 76.4% were male with a mean age of 68.5 years ±9.3 SD. Pain was evaluated with the CPOT, the Bhavioral Pain Scale (BPS) and with the Numeric Rating scale (NRS) at three time points (1. intubated + sedated, 2. intubated + awake, 3. extubated + awake) at rest and during nociceptive stimulus (positioning). Assessments were made separately by trained physicians and nursing staff.

RESULTS

Good results for interrater reliability and internal consistency could be demonstrated (weighted Cohen's kappa of 0.73, Cronbach's coefficient alpha of 0.8). Spearman correlation between CPOT and NRS was moderate but significant. The receiver operating characteristic (ROC) analysis to obtain optimal thresholds of CPOT to detect pain revealed different results during rest and stimulus and in intubated and extubated patients.

CONCLUSION

The validated German CPOT translation is a reliable tool for pain assessment in cardiac ICU patients in the absence of patients' ability for self-reporting. The use of this German version of CPOT now allows a better international comparability of corresponding data in future studies.

Optical Nanosensing of Lipid Accumulation due to Enzyme Inhibition in Live Cells

Drugs that influence enzymes of lipid metabolism can cause pathological accumulation of lipids in animal cells. Here, gold nanoparticles, acting as nanosensors that deliver surface-enhanced Raman scattering (SERS) spectra from living cells provide molecular evidence of lipid accumulation in lysosomes after treatment of cultured cells with the three tricyclic antidepressants (TCA) desipramine, amitryptiline, and imipramine. The vibrational spectra elucidate to great detail and with very high sensitivity the composition of the drug-induced lipid accumulations, also observed in fixed samples by electron microscopy and X-ray nanotomography. The nanoprobes show that mostly sphingomyelin is accumulated in the lysosomes but also other lipids, in particular, cholesterol. The observation of sphingomyelin accumulation supports the impairment of the enzyme acid sphingomyelinase. The SERS data were analyzed by random forest based approaches, in particular, by minimal depth variable selection and surrogate minimal depth (SMD), shown here to be particularly useful machine learning tools for the analysis of the lipid signals that contribute only weakly to SERS spectra of cells. SMD is used for the identification of molecular colocalization and interactions of the drug molecules with lipid membranes and for discriminating between the biochemical effects of the three different TCA molecules, in agreement with their different activity. The spectra also indicate that the protein composition is significantly changed in cells treated with the drugs.

X-ray tomography shows the varying three-dimensional morphology of gold nanoaggregates in the cellular ultrastructure

The processing of nanoparticles inside eukaryotic cells is a key step in many wanted and unwanted nano-bio-interactions. In order to understand the effects and functions of the intracellular aggregates that are formed, their properties and their interaction with the biological matrix must be characterized. High quality synchrotron soft X-ray tomography (SXT) data were obtained from cells containing gold nanoparticles that are commonly applied as tools for optical probing or drug delivery. 3D volume rendering of both cellular organelles and the nanoparticle aggregates of different sizes in the intact cells of two cell lines reveals variation in localization, size, shape and density of the intracellular gold nanoaggregates. The dependence of such variation on incubation time and cell type, as well as on the influence of pre-aggregation of primary nanoparticles is shown. The SXT results provide a detailed picture of intracellular aggregation and will improve the design of safe and efficient nanoparticle platforms for biomedical use.

Soft X-ray nanoscale imaging using a sub-pixel resolution charge coupled device (CCD) camera

A sub-pixel 16 bit charge coupled device camera featuring superresolution for the soft X-ray regime is presented. Superresolution images (SRIs) are reconstructed from a set of 4 × 4 individual low-resolution images that are recorded for different sub-pixel shifts of the detector. SRIs have a 1.3 times higher resolution than individual low-resolution images which is close to the maximum achievable enhancement factor of about 1.5 in the X-ray regime under ideal conditions. To characterize this camera and demonstrate its potential, an X-ray microscope setup is used to image different objects at different photon energies.

Position Statement: Linear prurigo is a subtype of chronic prurigo

BACKGROUND

Chronic prurigo (CPG) is a distinct disease characterized by chronic pruritus, history and/or signs of prolonged scratching and multiple pruriginous lesions. It may present with various clinical manifestations, including papules, nodules, plaques or umbilicated lesions. Some patients with chronic pruritus show pruriginous linear and scaring scratch lesions (LSSL) and it is unclear whether these lesions belong to the spectrum of CPG.

OBJECTIVE

To achieve a consensus on the classification of pruriginous LSSL and establish criteria to differentiate them from similar appearing conditions of different nature.

METHODS

Members of the Task Force Pruritus (TFP) of the European Academy of Dermatology and Venereology participated in the consensus conference, discussing representative clinical cases. Using the Delphi method, consensus was reached when ≥75% of members agreed on a statement.

RESULTS

Twenty-one members of the TFP with voting rights participated in the meeting. It was consented that LSSL occurs due to chronic pruritus and prolonged scratching, and share common pathophysiological mechanisms with CPG. LSSL were thus considered as belonging to the spectrum of CPG and the term 'linear prurigo' was chosen to describe this manifestation.

CONCLUSION

Considering linear prurigo as belonging to the spectrum of CPG has important clinical implications, since both the diagnostic and therapeutic approach of these patients should be performed as recommended for CPG. Importantly, linear prurigo should be differentiated from self-inflicted skin lesions as factitious disorders or skin picking syndromes. In the latter, artificial manipulation rather than pruritus itself leads to the development of cutaneous lesions, which can show clinical similarities to linear prurigo.

Relations between a standardized experimental stressor and cutaneous sensory function in patients with chronic pruritus and healthy controls: an experimental case-control study

Background

While chronic pruritus (CP) is a frequent symptom, many aspects of its underlying pathophysiological mechanisms still need elucidation. Research on sensory cutaneous function and on the influence of stress has been conducted mainly in patients with atopic dermatitis but is lacking for patients with CP.

Objective

To assess whether a standardized social stressor influences cutaneous sensory function in patients with CP in comparison with healthy controls (HC).

Methods

Case–control study; 33 CP and 30 HC were submitted to the standardized quantitative sensory testing protocol before and after the Trier Social Stress Test and 1 h later. Intraepidermal nerve fibre density (IENFD) was determined.

Results

Mechanical pain sensitivity and mechanical detection thresholds were significantly higher in CP than in HC, and mechanical detection thresholds increased more in CP than in HC over the three measurements. In both groups, cold pain threshold increased and heat pain threshold decreased from before to after the stress test and remained constant 1 h later. Only in CP, almost all QST tests induced at least a small amount of pruritus, which was not significantly altered by the stress test. IENFD in pruritic skin was significantly reduced in CP when compared to healthy controls.

Conclusion

Peripheral thermal sensory function was not altered in CP despite reduced IENFD in lesional skin, but we could demonstrate central sensitization processes specifically in CP and influences of an acute stressor inducing more sensitivity to thermal pain in both groups.

Characterization of degeneration phenomena in lithium-ion batteries by combined microscopic techniques

The application of detector strategies in scanning electron microscopy (SEM) correlated with computer tomography (CT) and light microscopy (LM) delivered unique new insights in degeneration effects of lithium-ion batteries. There we exemplary studied reference, cycled and storage cells. High-resolution SEM permit to visualize a coating on top of the cathode material of the treated cells for the first time, which also connects the conductive additives and battery active material. This confirms the assumption of a solid permeable interface on top of the cathode. The detection of low-loss reflected backscattered electrons for energies beyond 3 keV increases the available spatial resolution for material contrast. This offered the opportunity to address the atomic number of precipitates in the nm range inside the coating to be above carbon and below Li_1-x(Ni_1/3Mn_1/3Co_1/3)O₂ (NMC). Applying voltage contrast enables to show the difference in electronic conductivity of plate-like features on top of the cycled cell anode, most likely lithium plating. Cross sectional images of the anode delivered a significant change of the surficial-area morphology for the treated cells with increasing porosity. Precipitates were detected on top of the separator foil. An increment in thickness of the entire treated cells by computer tomography was found, which can be explained by the alteration of the anode, separator and cathode.

From SOMDA to application - integration strategies in the OR.NET demonstration sites

The effective development and dissemination of the open integration for the next generation of operating rooms require a comprehensive testing environment. In this paper, we present the various challenges to be addressed in demonstration applications, and we discuss the implementation approach, the foci of the demonstration sites and the evaluation efforts. Overall, the demonstrator setups have proven the feasibility of the service-oriented medical device architecture (SOMDA) and real-time approaches with a large variety of example applications. The applications demonstrate the potentials of open device interoperability. The demonstrator implementations were technically evaluated as well as discussed with many clinicians from various disciplines. However, the evaluation is still an ongoing research at the demonstration sites. Technical evaluation focused on the properties of a network of medical devices, latencies in data transmission and stability. A careful evaluation of the SOMDA design decisions and implementations are essential to a safe and reliable interoperability of integrated medical devices and information technology (IT) system in the especially critical working environment. The clinical evaluation addressed the demands of future users and stakeholders, especially surgeons, anesthesiologists, scrub nurses and hospital operators. The opinions were carefully collected to gain further insights into the potential benefits of the technology and pitfalls in future work.

[Imaging and biopsy of soft tissue tumors]

Soft tissue tumors represent a special challenge in interdisciplinary cooperation. Malignant tumors require a multimodal therapy concept so that patient treatment in a specialized tumor center is recommended. The task of the surgeon in close cooperation with the radiologist is the resection of the tumor in sano with the required safety margin. The aim of diagnostic imaging is to describe the primary expansion of the tumor size and a possible tumor infiltration of adjacent compartments. The most important diagnostic imaging for this purpose is magnetic resonance imaging (MRI), especially T1-weighted fat-suppressed gadolinium-enhanced sequences. Together with T2-weighted sequences a reliable differentiation between necrosis and vital tumor tissue is possible, which enables a targeted biopsy of vital tumor tissue. For the differentiation between benign and malignant soft tissue tumors and for determination of histological differentation a core needle biopsy, either computer tomography-guided or under sonographic control and increasingly more by MRI guidance, is currently the gold standard in most tumor centers. A representative biopsy from vital tumor tissue leads to the diagnosis with a very high degree of certainty.

Characterisation of anticancer peptides at the single-cell level

The development of efficacious anticancer therapeutics is difficult due to the heterogeneity of the cellular response to chemotherapy. Anticancer peptides (ACPs) are promising drug candidates that have been shown to be active against a range of cancer cells. However, few ACP studies focus on tumour single-cell heterogeneities. In order to address this need, we developed a microfluidic device and an imaging procedure that enable the capture, monitoring, and analysis of several hundred single cells for the study of drug response. MCF-7 human breast adenocarcinoma cells were captured in hydrodynamic traps and isolated in individual microchambers of less than 100 pL volume. With pneumatic valves, different sets of microchambers were actuated to expose the cells to various drugs. Here, the effect of three membranolytic ACPs - melittin, aurein 1.2 and aurein 2.2 - was investigated by monitoring the efflux of calcein from single MCF-7 cells. The loss of membrane integrity was observed with two different strategies that allow either focusing on one cell for mechanistic studies or parallel analysis of hundreds of individual cells. In general, the device is applicable to the analysis of the effect of various drugs on a large number of different cell types. The platform will enable us in the future to determine the origin of heterogeneous responses on pharmacological substances like ACPs within cell populations by combining it with other on-chip analytical methods.