Programming of neural progenitors of the adult subependymal zone towards a glutamatergic neuron lineage by neurogenin 2.

Although adult subependymal zone (SEZ) neural stem cells mostly generate GABAergic interneurons, a small progenitor population expresses the proneural gene Neurog2 and produces glutamatergic neurons. Here, we determined whether Neurog2 could respecify SEZ neural stem cells and their progeny toward a glutamatergic fate. Retrovirus-mediated expression of Neurog2 induced the glutamatergic lineage markers TBR2 and TBR1 in cultured SEZ progenitors, which differentiated into functional glutamatergic neurons. Likewise, Neurog2-transduced SEZ progenitors acquired glutamatergic neuron hallmarks in vivo. Intriguingly, they failed to migrate toward the olfactory bulb and instead differentiated within the SEZ or the adjacent striatum, where they received connections from local neurons, as indicated by rabies virus-mediated monosynaptic tracing. In contrast, lentivirus-mediated expression of Neurog2 failed to reprogram early SEZ neurons, which maintained GABAergic identity and migrated to the olfactory bulb. Our data show that NEUROG2 can program SEZ progenitors toward a glutamatergic identity but fails to reprogram their neuronal progeny.

[Digital guidelines of the twenty-first century : Requirements for the structured development, application and evaluation of medical knowledge]. / Digitale Leitlinien des 21. Jahrhunderts : Anforderungen an die strukturierte Entwicklung, Anwendung und Evaluation medizinischen Wissens.

Until now, clinical guidelines have been understood as generalized representations of clinical knowledge that, based on best available evidence, show the requirements for patient care in specific patient situations. This expert opinion article is intended to discuss how digital guidelines should be designed and which requirements must be met for the structured development, application and evaluation of such guidelines. The digitalization of guidelines must take into account the transformation of analogue text-based guideline information into formats that enable human-machine interaction via user interfaces, that show physicians the requirements for guideline-compliant patient care and that also enable machine storage, machine execution and machine processing of patient data.

Results from the "Me & My Heart" (eMocial) Study: a Randomized Evaluation of a New Smartphone-Based Support Tool to Increase Therapy Adherence of Patients with Acute Coronary Syndrome.

PURPOSE: This study evaluated whether patient support, administered via an electronic device-based app, increased adherence to treatment and lifestyle changes in patients with acute coronary syndrome (ACS) treated with ticagrelor in routine clinical practice. METHODS: Patients (aged ≥ 18 years) with diagnosed ACS treated with ticagrelor co-administered with low-dose acetylsalicylic acid were randomized into an active group (with support tool app for medication intake reminders and motivational messages) and a control group (without support tool app), and observed for 48 weeks (ClinicalTrials.gov Identifier: NCT02615704). Patients were asked to complete the 36-item Short-Form Health Survey (SF-36) and Lifestyle Changes Questionnaire (LSQ), and were assessed for blood pressure and body mass index (BMI) at baseline (visit 1) and at the end of the study (visit 2). Medication adherence was measured using the Brilique Adherence Questionnaire (BAQ). RESULTS: Patients (N = 676) were randomized to an active (n = 342) or a control (n = 334) group. BAQ data were available for 174 patients in the active group and 174 patients in the control group. Over the 48-week period, mean (standard deviation) adherence for the active and control groups was 96.4% (13.2%) and 91.5% (23.1%), respectively (effect of app intervention, p < 0.05). There were no significant differences in blood pressure and BMI between visits. General improvements in SF-36 and LSQ scores were observed for both groups. CONCLUSION: The patient support tool app was associated with significant improvements in patient-reported treatment adherence compared with a data collection app alone in patients prescribed ticagrelor for ACS.

Outcome of a polymer-free drug-coated coronary stent in bifurcation lesions-Pilot registry with serial OCT imaging.

BACKGROUND: Polymer-free and carrier-free drug-coated stents (DCS) represent a novel therapeutic option for the treatment of coronary artery disease. The objective of this pilot registry is to evaluate the safety and efficacy of DCS implantation in bifurcation lesions. METHODS: Overall, 23 consecutive patients with 24 lesions received a Biolimus A9-coated DCS for coronary bifurcation lesions. Patients were examined with quantitative coronary angiography (QCA) and optical coherence tomography (OCT) at 3-6 months of follow-up. RESULTS: A total of 23 patients with 24 bifurcation lesions were included in this study. Nine (33.3%) lesions of eight patients revealed angiographical target lesion failure due to in-stent restenosis (ISR). In total, 19 patients with 20 bifurcation lesions were suitable for OCT analysis. A total of 2936 struts were analyzed and 14 struts (0.47%) were classified as malapposed. The mean luminal area (mm2) was not different in lesions with ISR vs. lesions with no ISR (5.07 ± 2.0 vs. 5.73 ± 1.34, p = 0.39) at follow-up. Lesions with ISR showed higher mean neointimal burden (27.11 ± 10.59 vs. 13.93 ± 9.16%, respectively; p = 0.009). All of the patients who presented with significant ISR required percutaneous re-intervention. CONCLUSIONS: We observed a high rate of DCS ISR in bifurcation lesions, possibly related to increased inflammation and neoatherosclerosis. The small size of the study warrants careful interpretation of our results. Larger trials are necessary to expand knowledge of these findings.

The focal adhesion protein ß-parvin controls cardiomyocyte shape and sarcomere assembly in response to mechanical load.

Physiological and pathological cardiac stress induced by exercise and hypertension, respectively, increase the hemodynamic load for the heart and trigger specific hypertrophic signals in cardiomyocytes leading to adaptive or maladaptive cardiac hypertrophy responses involving a mechanosensitive remodeling of the contractile cytoskeleton. Integrins sense load and have been implicated in cardiac hypertrophy, but how they discriminate between the two types of cardiac stress and translate mechanical loads into specific cytoskeletal signaling pathways is not clear. Here, we report that the focal adhesion protein ß-parvin is highly expressed in cardiomyocytes and facilitates the formation of cell protrusions, the serial assembly of newly synthesized sarcomeres, and the hypertrophic growth of neonatal rat ventricular cardiomyocytes (NRVCs) in vitro. In addition, physiological mechanical loading of NRVCs by either the application of cyclic, uni-axial stretch, or culture on physiologically stiff substrates promotes NRVC elongation in a ß-parvin-dependent manner, which is achieved by binding of ß-parvin to α/ß-PIX, which in turn activates Rac1. Importantly, loss-of-function studies in mice also revealed that ß-parvin is essential for the exercise-induced cardiac hypertrophy response in vivo. Our results identify ß-parvin as a novel mechano-responsive signaling hub in hypertrophic cardiomyocytes that drives cell elongation in response to physiological mechanical loads.

Selective plasticity of callosal neurons in the adult contralesional cortex following murine traumatic brain injury.

Traumatic brain injury (TBI) results in deficits that are often followed by recovery. The contralesional cortex can contribute to this process but how distinct contralesional neurons and circuits respond to injury remains to be determined. To unravel adaptations in the contralesional cortex, we used chronic in vivo two-photon imaging. We observed a general decrease in spine density with concomitant changes in spine dynamics over time. With retrograde co-labeling techniques, we showed that callosal neurons are uniquely affected by and responsive to TBI. To elucidate circuit connectivity, we used monosynaptic rabies tracing, clearing techniques and histology. We demonstrate that contralesional callosal neurons adapt their input circuitry by strengthening ipsilateral connections from pre-connected areas. Finally, functional in vivo two-photon imaging demonstrates that the restoration of pre-synaptic circuitry parallels the restoration of callosal activity patterns. Taken together our study thus delineates how callosal neurons structurally and functionally adapt following a contralateral murine TBI.

Efficacy and safety of ECG-synchronized pulsatile extracorporeal membrane oxygenation in the clinical setting: The SynCor Trial.

INTRODUCTION: Mechanical circulatory support (MCS) devices are increasingly used as a treatment option in resuscitation or in patients with cardiogenic shock (CS). Prophylactic implantation in high-risk percutaneous coronary interventions (HRPCI) is another upcoming indication. The i-cor ECG-synchronized cardiac assist device combines the hemodynamic support of a veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with the ability to generate a pulsatile flow and thus decreasing adverse effects of VA-ECMO on myocardial function. Aim of this study was to obtain data concerning feasibility, safety and outcomes in both indications. METHODS: A total of 47 patients (34 HRPCI, 13 CS) were included in nine German centers and participated in this study. Demographic and clinical parameters, procedural as well as follow-up data were prospectively recorded and analyzed. RESULTS: Device implantation and initiation of ECG-synchronized cardiac assist was technical successful in all cases and no failures of the consoles or disposable parts were observed. Furthermore, intended percutaneous coronary interventions and successful weaning from cardiac assist was achieved in 97.1% of HRPCI patients. We observed a 30d-survival of 94.1% in the HRPCI group and 69.2% in the CS group. Main complications in both groups were bleeding events (14.7% HRPCI, 23.1% CS) and critical limb ischemia (2.9% HRPCI, 38.5% CS). CONCLUSION: The i-cor ECG-synchronized cardiac assist device appears safe and feasible showing clinical outcomes comparable to existing data in the setting of high-risk percutaneous coronary interventions and acute cardiogenic shock. Further prospective trials are warranted to identify optimal patient and interventional characteristics that will benefit most of this novel kind of mechanical circulatory support.

Inhibition of Rac1 GTPase Decreases Vascular Oxidative Stress, Improves Endothelial Function, and Attenuates Atherosclerosis Development in Mice.

Aims: Oxidative stress and inflammation contribute to atherogenesis. Rac1 GTPase regulates pro-oxidant NADPH oxidase activity, reactive oxygen species (ROS) formation, actin cytoskeleton organization and monocyte adhesion. We investigated the vascular effects of pharmacological inhibition of Rac1 GTPase in mice. Methods and Results: We treated wild-type and apolipoprotein E-deficient (ApoE-/-) mice with Clostridium sordellii lethal toxin (LT), a Rac1 inhibitor, and assessed vascular oxidative stress, expression and activity of involved proteins, endothelial function, macrophage infiltration, and atherosclerosis development. LT-treated wild-type mice displayed decreased vascular NADPH oxidase activity and ROS production. Therapeutic LT doses had no impact on behavior, food intake, body weight, heart rate, blood pressure, vascular and myocardial function, differential blood count, and vascular permeability. ApoE-/- mice were fed a cholesterol-rich diet and were treated with LT or vehicle. LT treatment led to decreased aortic Rac1 GTPase activity, NADPH oxidase activity and ROS production, but had no impact on expression and membrane translocation of NADPH oxidase subunits and RhoA GTPase activity. LT-treated mice showed improved aortic endothelium-dependent vasodilation, attenuated atherosclerotic lesion formation and reduced macrophage infiltration of atherosclerotic plaques. Concomitant treatment of cholesterol-fed ApoE-/- mice with LT, the specific synthetic Rac1 inhibitor NSC 23766 or simvastatin comparably reduced aortic Rac1 activity, NADPH oxidase activity, oxidative stress, endothelial dysfunction, atherosclerosis development, and macrophage infiltration. Conclusions: These findings identify an important role of the small GTPase Rac1 in atherogenesis and provide a potential target for anti-atherosclerotic therapy.

High-Yield Human Induced Pluripotent Stem Cell-Derived Monocytes and Macrophages Are Functionally Comparable With Primary Cells.

Macrophages are pivotal effectors of host immunity and regulators of tissue homeostasis. Understanding of human macrophage biology has been hampered by the lack of reliable and scalable models for cellular and genetic studies. Human induced pluripotent stem cell (hiPSC)-derived monocytes and macrophages, as an unlimited source of subject genotype-specific cells, will undoubtedly play an important role in advancing our understanding of macrophage biology and implication in human diseases. In this study, we present a fully optimized differentiation protocol of hiPSC-derived monocytes and granulocyte-macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF). We present characterization of iPSC-derived myeloid lineage cells at phenotypic, functional, and transcriptomic levels, in comparison with corresponding subsets of peripheral blood-derived cells. We also highlight the application of hiPSC-derived monocytes and macrophages as a gene-editing platform for functional validation in research and drug screening, and the study also provides a reference for cell therapies.

Left atrial appendage occlusion with the Amplatzer Amulet: update on device sizing.

PURPOSE: The present paper analyzes the role of different imaging modalities for left atrial appendage (LAA) assessment and the recommended specific measurements to improve device selection with regard to the Amulet device. BACKGROUND: Morphological LAA assessment is one of the pivotal factors to achieve proper LAA sealing and potentially reduce the risk of complications by minimizing manipulation inside the appendage. METHODS: Eight experienced physicians in LAAO were asked to contribute in the preparation of a device sizing consensus manuscript after comprehensive assessment of previous published data on LAA imaging/measurement. RESULTS: LAA morphology is often complex and requires more detailed spatial resolution and 3-dimensional assessments to reduce the risk of mis-sizing. Traditionally, upsizing of devices based upon the largest measured LAA diameters have been used. However, this may lead to oversizing in markedly elliptical appendages. Thus, when 3D imaging modalities are available, utilizing the LAA mean diameters might be a better alternative. Operators should also note the systematic biases in differences in measurements obtained with different imaging modalities, with CT giving the largest measurements, followed by 3D-TEE, and then 2D-TEE and angiography. In fact, for 2D imaging techniques (2D-TEE and angiography), LAA diameters tend to be underestimated, and therefore, LAA largest diameters seem to be still the best option for device sizing. Some specific anatomies such as proximal chicken-wing or conic LAAs may require different measurements and implantations to achieve implant success. CONCLUSIONS: In conclusion, LAA mean diameters might be a better alternative to largest diameters when 3D imaging modalities are available.

Mitochondria-Endoplasmic Reticulum Contacts in Reactive Astrocytes Promote Vascular Remodeling.

Astrocytes have emerged for playing important roles in brain tissue repair; however, the underlying mechanisms remain poorly understood. We show that acute injury and blood-brain barrier disruption trigger the formation of a prominent mitochondrial-enriched compartment in astrocytic endfeet, which enables vascular remodeling. Integrated imaging approaches revealed that this mitochondrial clustering is part of an adaptive response regulated by fusion dynamics. Astrocyte-specific conditional deletion of Mitofusin 2 (Mfn2) suppressed perivascular mitochondrial clustering and disrupted mitochondria-endoplasmic reticulum (ER) contact sites. Functionally, two-photon imaging experiments showed that these structural changes were mirrored by impaired mitochondrial Ca2+ uptake leading to abnormal cytosolic transients within endfeet in vivo. At the tissue level, a compromised vascular complexity in the lesioned area was restored by boosting mitochondrial-ER perivascular tethering in MFN2-deficient astrocytes. These data unmask a crucial role for mitochondrial dynamics in coordinating astrocytic local domains and have important implications for repairing the injured brain.

Design and rationale for the "Me & My Heart" (eMocial) study: A randomized evaluation of a new smartphone-based support tool to increase therapy adherence of patients with acute coronary syndrome.

A novel smartphone-based patient support tool was developed to increase the adherence to antiplatelet therapy and lifestyle changes in patients after coronary angioplasty for acute coronary syndrome (ACS). The eMocial study (ClinicalTrials.gov Identifier: NCT02615704) investigates whether an electronic support tool will improve adherence to comedication and lifestyle changes in ACS patients. The primary hypothesis of this trial is that an electronic support tool can increase adherence to comedication (primary endpoint) thereby supporting positive lifestyle changes (secondary endpoints). Patients hospitalized with ACS (ST elevation myocardial infarction [STEMI], non-ST elevation myocardial infarction [NSTEMI], or unstable angina pectoris) and treated with ticagrelor coadministered with low-dose acetylsalicylic acid will be randomized 1:1 to an active group receiving the patient support tool via a smartphone-based application or to a control group without the patient support tool. Patient questionnaires to evaluate lifestyle changes and quality of life will be used at baseline and at the end of the 48-week observation phase. Patients are asked to fill out questionnaires to determine their adherence, treatment attitudes, health-care utilization and risk factors on a monthly basis. The study was started in February 2016 and the completion date is scheduled for October 2019. For final analysis 664 patients are expected be available. Preliminary baseline demographics were unstable angina pectoris (13.7%), NSTEMI (49.9%), STEMI (36.4%), male gender (86.3%), and diabetes mellitus (17.6%). Our study could significantly help to understand how inadequate adherence to antiplatelet therapy in ACS patients could be improved with a smartphone-based application.

Cryo EM structure of the rabies virus ribonucleoprotein complex.

Rabies virus is an important zoonotic pathogen. Its bullet shaped particle contains a helical nucleocapsid. We used cryo-electron tomography and subsequent subtomogram averaging to determine the structure of its ribonucleoprotein. The resulting electron density map allowed for confident fitting of the N-protein crystal structure, indicating that interactions between neighbouring N-proteins are only mediated by N- and C-terminal protruding subdomains (aa 1-27 and aa 355-372). Additional connecting densities, likely stabilizing the ribonucleoprotein complex, are present between neighbouring M-protein densities on the same helical turn and between M- and N-protein densities located on neighbouring helical turns, but not between M-proteins of different turns, as is observed for the related Vesicular stomatitis virus (VSV). This insight into the architecture of the rabies virus nucleocapsid highlights the surprising structural divergence of large biological assemblies even if the building blocks - here exemplified by VSV M- and N-protein - are structurally closely related.

Treatment with mononuclear cell populations improves post-infarction cardiac function but does not reduce arrhythmia susceptibility.

BACKGROUND: Clinical and experimental data give evidence that transplantation of stem and progenitor cells in myocardial infarction could be beneficial, although the underlying mechanism has remained elusive. Ventricular tachyarrhythmia is the most frequent and potentially lethal complication of myocardial infarction, but the impact of mono nuclear cells on the incidence of ventricular arrhythmia is still not clear. OBJECTIVE: We aimed to characterize the influence of splenic mononuclear cell populations on ventricular arrhythmia after myocardial infarction. METHODS: We assessed electrical vulnerability in vivo in mice with left ventricular cryoinfarction 14 days after injury and intramyocardial injection of specific subpopulations of mononuclear cells (MNCs) (CD11b-positive cells, Sca-1-positive cells, early endothelial progenitor cells (eEPCs)). As positive control group we used embryonic cardiomyocytes (eCMs). Epicardial mapping was performed for analysing conduction velocities in the border zone. Left ventricular function was quantified by echocardiography and left heart catheterization. RESULTS: In vivo pacing protocols induced ventricular tachycardia (VT) in 30% of non-infarcted mice. In contrast, monomorphic or polymorphic VT could be evoked in 94% of infarcted and vehicle-injected mice (p<0.01). Only transplantation of eCMs prevented post-infarction VT and improved conduction velocities in the border zone in accordance to increased expression of connexin 43. Cryoinfarction resulted in a broad aggravation of left ventricular function. All transplanted cell types augmented left ventricular function to a similar extent. CONCLUSIONS: Transplantation of different MNC populations after myocardial infarction improves left ventricular function similar to effects of eCMs. Prevention of inducible ventricular arrhythmia is only seen after transplantation of eCMs.

Neuron-specific-enolase as a predictor of the neurologic outcome after cardiopulmonary resuscitation in patients on ECMO.

BACKGROUND: Neuron-specific-enolase (NSE) is frequently used to predict the neurologic outcome in persistently unconscious patients after cardiopulmonary resuscitation (CPR). However, its predictive value is unclear in the setting of veno-arterial extracorporeal membrane oxygenation therapy (ECMO). Aim of this project is to evaluate the predictive value of NSE in ECMO patients. METHODS: NSE was measured after 24, 48, and 72 h in post-CPR ECMO patients. Neurologic status was evaluated using the best Cerebral Performance Categories Score (CPC) during the hospital stay. Patients who deceased within the first 24 h and patients who were awake during the first 24 h were excluded. ROC curves were calculated to assess the discriminative ability of single NSE measurements. Trajectories of serial NSE values were investigated using latent class mixed models. RESULTS: The derivation cohort consisted of 65 patients, 30-day all-cause mortality was 47.7% and a poor neurological outcome with a CPC score of 4-5 was seen 30.7%. NSE measurement after 48 h showed the best discrimination for poor neurological outcome (AUC of 0.87 in the ROC curve; cut-off value of 70 µg/L). Specificity was highest if using serial NSE measurements at all three time points. These results could be validated in an external cohort of 64 patients. CONCLUSION: In post-CPR patients on ECMO, NSE can be used to assess the neurologic outcome. Importantly, specificity was highest if using serial NSE measurements. Further research using prospective datasets is needed to verify these findings.

Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR): consensus statement of DGIIN, DGK, DGTHG, DGfK, DGNI, DGAI, DIVI and GRC.

Extracorporeal cardiopulmonary resuscitation (eCPR) may be considered as a rescue attempt for highly selected patients with refractory cardiac arrest and potentially reversible aetiology. Currently, there are no randomised, controlled studies on eCPR. Thus, prospective validated predictors of benefit and outcome are lacking. Currently, selection criteria and procedure techniques differ across hospitals and standardised algorithms are lacking. Based on expert opinion, the present consensus statement provides a first standardised treatment algorithm for eCPR.