ABSTRACT
MIF is a ubiquitous protein involved in proinflammatory processes, which undergoes an oxidation-driven conformational change to oxidized (ox)MIF. We demonstrate that hypochlorous acid, produced by neutrophil-released myeloperoxidase (MPO) under inflammatory conditions, effectively oxidizes MIF into the oxMIF isoform, which is specifically recognized by the anti-oxMIF therapeutic antibody, ON104. NMR investigation of MIF oxidized by the MPO system revealed increased flexibility throughout the MIF structure, including at several catalytic and allosteric sites. Mass spectrometry of MPO-oxMIF revealed methionines as the primary site of oxidation, whereas Pro2 and Tyr99/100 remained almost unmodified. ELISA, SPR and cell-based assays demonstrated that structural changes caused by MPO-driven oxidation promoted binding of oxMIF to its receptor, CD74, which does not occur with native MIF. These data reveal the environment and modifications that facilitate interactions between MIF and its pro-inflammatory receptor, and a route for therapeutic intervention targeting the oxMIF isoform.
Subject(s)
Antigens, Differentiation, B-Lymphocyte , Histocompatibility Antigens Class II , Intramolecular Oxidoreductases , Macrophage Migration-Inhibitory Factors , Oxidation-Reduction , Protein Binding , Macrophage Migration-Inhibitory Factors/metabolism , Macrophage Migration-Inhibitory Factors/chemistry , Humans , Antigens, Differentiation, B-Lymphocyte/metabolism , Antigens, Differentiation, B-Lymphocyte/chemistry , Histocompatibility Antigens Class II/metabolism , Histocompatibility Antigens Class II/chemistry , Intramolecular Oxidoreductases/metabolism , Intramolecular Oxidoreductases/chemistry , Peroxidase/metabolismABSTRACT
The encapsulation of HIV-unrelated T helper peptides into liposomal vaccines presenting trimers of the HIV-1 envelope glycoprotein (Env) on the surface (T helper liposomes) may recruit heterologous T cells to provide help for Env-specific B cells. This mechanism called intrastructural help can modulate the HIV-specific humoral immune response. In this study, we used cationic T helper liposomes to induce intrastructural help effects in a small animal model. The liposomes were functionalized with Env trimers by a tag-free approach designed to enable a simplified GMP production. The pre-fusion conformation of the conjugated Env trimers was verified by immunogold electron microscopy (EM) imaging and flow cytometry. The liposomes induced strong activation of Env-specific B cells in vitro. In comparison to previously established anionic liposomes, cationic T helper liposomes were superior in CD4+ T cell activation after uptake by dendritic cells. Moreover, the T helper liposomes were able to target Env-specific B cells in secondary lymphoid organs after intramuscular injection. We also observed efficient T helper cell activation and proliferation in co-cultures with Env-specific B cells in the presence of cationic T helper liposomes. Mouse immunization experiments with cationic T helper liposomes further revealed a modulation of the Env-specific IgG subtype distribution and enhancement of the longevity of antibody responses by ovalbumin- and Hepatitis B (HBV)-specific T cell help. Thus, clinical evaluation of the concept of intrastructural help seems warranted.
Subject(s)
HIV Infections , HIV-1 , Vaccines , Animals , Mice , Liposomes/chemistry , HIV Antibodies , env Gene Products, Human Immunodeficiency Virus/chemistry , Immunity, HumoralABSTRACT
Macrophage Migration Inhibitory Factor (MIF) is a pleiotropic inflammatory cytokine that emerged as a pivotal regulator in the pathogenesis of several autoimmune diseases including rheumatoid arthritis (RA). MIF occurs in two immunologically distinct conformational isoforms, indicated as reduced (redMIF) and oxidized MIF (oxMIF) where the latter exerts disease-related activities. In this study we demonstrate the presence of circulating oxMIF in RA patients and investigate the in vivo effects of an oxMIF-neutralizing antibody in a murine model of RA. By advanced antibody engineering we generated the fully human anti-oxMIF antibody ON104 with abolished effector functions. The therapeutic potential of ON104 was tested in a model of Collagen-Induced Arthritis (CIA) in DBA/1j mice. At disease onset, the mice received ON104 twice a week for three weeks. Clinical symptoms were assessed daily, and histological examinations of the joints were performed at the end of the study. Antibody ON104, specifically targeting human and murine oxMIF, is highly affine and does not elicit effector functions in vitro. The treatment of CIA mice with ON104 profoundly modulated disease progression with marked amelioration of clinical signs of arthritis that was associated with reduced synovial and cartilage damage and reduced F4/80-positive macrophages in the joints. These data prove that oxMIF is a relevant target in a well-known model of human RA and its specific neutralization by the antibody ON104 ameliorates clinical and histological signs of the disease in the so-treated mice. Thus, ON104 represents a new and promising treatment option for RA and possibly other autoimmune diseases.
Subject(s)
Arthritis, Experimental , Arthritis, Rheumatoid , Macrophage Migration-Inhibitory Factors , Humans , Mice , Animals , Arthritis, Experimental/chemically induced , Arthritis, Experimental/drug therapy , Antibodies, Monoclonal/therapeutic use , Mice, Inbred DBAABSTRACT
Objectives: Animal assisted intervention is an increasingly accepted tool to improve human well-being. The present study was performed to assess whether dog assisted education has a positive effect on children suffering from rheumatic disorders with pain and adolescents with chronic pain syndrome. Design: Two groups of juvenile patients were recruited: 7-17-year-old children in children with rheumatic diseases and adolescents with chronic pain syndromes. Overall, n=26 participated in the intervention, and n=29 in the control group. Setting: The intervention group met once a month, 12 times overall, for working with man trailing dogs in various locations. Main outcome measures: The influence of dog assisted education on quality of life (PedsQLTM Scoring Algorithm), pain intensity, perception, coping (Paediatric Pain Coping Inventory-Revised), and state anxiety (State Trait Anxiety Inventory) was assessed. Results: The quality of life increased significantly in the investigated period, but for both, the intervention and the control group. The state anxiety of children was lower after the dog assisted education than before. After the dog training sessions, state anxiety was 18% to 30% lower than before the intervention. Some participants noted subjectively improved pain coping and changes in pain perception, which were not found in the data. Conclusion: Our results indicate that for children with rheumatic diseases and adolescents with chronic pain syndromes dog assisted education (1) might lead to an increase of the quality of life, (2) leads to decreased state anxiety from pre to post intervention and (3) does not influence pain perception, frequency and intensity.
Subject(s)
Chronic Pain , Rheumatic Diseases , Male , Humans , Child , Dogs , Adolescent , Animals , Chronic Pain/therapy , Quality of Life , Syndrome , Rheumatic Diseases/epidemiology , GermanyABSTRACT
High levels of macrophage migration inhibitory factor (MIF) in patients with cancer are associated with poor prognosis. Its redox-dependent conformational isoform, termed oxidized MIF (oxMIF), is a promising tumor target due to its selective occurrence in tumor lesions and at inflammatory sites. A first-generation anti-oxMIF mAb, imalumab, was investigated in clinical trials in patients with advanced solid tumors, where it was well tolerated and showed signs of efficacy. However, imalumab has a short half-life in humans, increased aggregation propensity, and an unfavorable pharmacokinetic profile. Here, we aimed to optimize imalumab by improving its physicochemical characteristics and boosting its effector functions. Point mutations introduced into the variable regions reduced hydrophobicity and the antibodies' aggregation potential, and increased plasma half-life and tumor accumulation in vivo, while retaining affinity and specificity to oxMIF. The introduction of mutations into the Fc region known to increase antibody-dependent cellular cytotoxicity resulted in enhanced effector functions of the novel antibodies in vitro, whereas reduced cytokine release from human peripheral blood mononuclear cells in the absence of target antigen by the engineered anti-oxMIF mAb ON203 versus imalumab reveals a favorable in vitro safety profile. In vivo, ON203 mAb demonstrated superior efficacy over imalumab in both prophylactic and established prostate cancer (PC3) mouse xenograft models. In summary, our data highlight the potential of the second-generation anti-oxMIF mAb ON203 as a promising immunotherapy for patients with solid tumors, warranting clinical evaluation.
Subject(s)
Antineoplastic Agents , Macrophage Migration-Inhibitory Factors , Prostatic Neoplasms , Male , Mice , Animals , Humans , Macrophage Migration-Inhibitory Factors/genetics , Macrophage Migration-Inhibitory Factors/chemistry , Leukocytes, Mononuclear , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/therapeutic use , Prostatic Neoplasms/drug therapyABSTRACT
BACKGROUND: Renal denervation (RDN) can reduce cardiac sympathetic activity maintained by arterial hypertension (aHT). Its potential antiarrhythmic effect on rhythm outcome in patients with multi-drug resistant aHT undergoing catheter ablation for atrial fibrillation (AF) is unclear. METHODS: The RDN+AF study was a prospective, randomized, two-center trial. Patients with paroxysmal or persistent AF and uncontrolled aHT (mean systolic 24-h ambulatory BP > 135 mmHg) despite taking at least three antihypertensive drugs were enrolled. Patients were 1:2 randomized to either RDN+AF ablation or AF-only ablation. Primary endpoint was freedom from any AF episode > 2 min at 12 months assessed by implantable loop recorder (ILR) or 7d-holter electrocardiogram. Secondary endpoints included rhythm outcome at 24 months, blood pressure control, periprocedural complications, and renovascular safety. RESULTS: The study randomized 61 patients (mean age 65 ± 9 years, 53% men). At 12 months, RDN+AF patients tended to have a greater decrease in ambulatory BPs but did not reach statistical significance. No differences in rhythm outcome were observed. Freedom from AF recurrence in the RDN+AF and AF-only group measured 61% versus 53% p = .622 at 12 months and 39% versus 47% p = .927 at 24 months, respectively. Periprocedural complications occurred in 9/61 patients (15%). No patient died. CONCLUSION: Among patients with multidrug-resistant aHT and paroxysmal or persistent AF, concomitant RDN+AF ablation was not associated with better blood pressure control or rhythm outcome in comparison to AF-only ablation and medical therapy.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Hypertension , Male , Humans , Middle Aged , Aged , Female , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Atrial Fibrillation/complications , Prospective Studies , Treatment Outcome , Hypertension/diagnosis , Hypertension/surgery , Sympathectomy/adverse effects , Catheter Ablation/adverse effects , RecurrenceABSTRACT
Background: Interventional cardiac magnetic resonance (iCMR) has been established as a radiation-free alternative compared to standard fluoroscopy-guided catheter ablation for cavotricuspid isthmus (CTI)-dependent atrial flutter to image anatomy, structural alterations, and further catheter guidance. Objective: The purpose of this study was to explore the safety, feasibility, and efficacy of CTI ablations performed completely in the iCMR suite using active catheter imaging. Methods: Consecutive patients underwent iCMR-guided catheter ablation for CTI-dependent atrial flutter. Procedures were performed in a 1.5-T magnetic resonance (MR) imaging unit with MR-conditional ablation catheters. Catheter guidance was achieved using active catheter imaging via integrated MR receive tip coils. Acute success, periprocedural complications, and short-term follow-up were collected for further analysis. Results: All patients (N = 15; 73% male; median age 70 years; interquartile range [67-82]) achieved acute procedural success without any complication. Median procedural time was 43 minutes [33-58] with median radiofrequency delivery time of 18 minutes [12-26]. Postprocedural lesion visualization scanning was completed in a median of 32 minutes [10-42]. None of the patients with 6-month follow-up had atrial flutter recurrence. Conclusion: In the iCMR suite, CTI-dependent atrial flutter ablation could be achieved safely using active catheter imaging without any complication. It further allows detailed anatomic visualization of the CTI, intraprocedural lesion visualization, and exclusion of pericardial effusion.
ABSTRACT
BACKGROUND: Clinically effective ablation approaches for patients with persistent atrial fibrillation (AF) are still being debated. So far, ablation targets and strategies beyond pulmonary vein isolation (PVI) have failed to show systematic outcome improvement in randomized controlled clinical trials. METHODS: We conducted a multicenter, randomized trial to determine whether PVI plus individualized substrate ablation of atrial low-voltage myocardium improves outcome in patients with persistent AF. We randomly assigned 324 patients in a 1:1 ratio to receive PVI alone (163 patients; PVI only) or PVI plus substrate modification (161 patients; PVI+SM). The primary study end point was the first recurrence of an atrial arrhythmia longer than 30 seconds after single ablation, with 3 months blanking, using serial 7-day electrocardiogram recordings over 12 months of observation. Patients were also encouraged to receive implantable cardiac monitors. RESULTS: The primary study end point occurred in 75 PVI-only patients (50%) and in 54 PVI+SM patients (35%) (KaplanMeier event rate estimates: hazard ratio=0.62, 95% confidence interval [CI]=0.43 to 0.88, log rank P=0.006). Adverse events occurred in three PVI-only patients (1.8%) and in six PVI+SM patients (3.7%) (difference: −1.9 percentage points, 95% CI=−5.5 to 1.7 percentage points). Implant monitoring was used in 242 patients. Among them, 65 PVI-only patients (55%) versus 47 PVI+SM patients (39%) experienced recurrences (difference: 15 percentage points, 95% CI=3 to 28 percentage points). CONCLUSIONS: In this randomized trial, PVI plus individualized ablation of atrial low-voltage myocardium significantly improved outcomes in patients with persistent AF. (ClinicalTrials.gov number, NCT02732626.)
Subject(s)
Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Humans , Myocardium , Recurrence , Treatment OutcomeABSTRACT
[Figure: see text].
Subject(s)
Atrial Appendage/surgery , Atrial Fibrillation/surgery , Cardiac Surgical Procedures/methods , Cardiomyopathies/complications , Myocardium/pathology , Stroke/prevention & control , Aged , Atrial Appendage/diagnostic imaging , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Cardiomyopathies/diagnosis , Cardiomyopathies/surgery , Feasibility Studies , Female , Fibrosis/complications , Fibrosis/diagnosis , Follow-Up Studies , Heart Atria/diagnostic imaging , Heart Atria/surgery , Humans , Imaging, Three-Dimensional , Male , Prospective Studies , Stroke/etiology , Tomography, X-Ray ComputedABSTRACT
BACKGROUND: Inflammation is a key process during atherosclerotic lesion development and propagation. Recent evidence showed clearly that especially the inhibition of interleukin (IL)-1ß reduced atherosclerotic adverse events in human patients. Fatty acid oxidation (FAO) was previously demonstrated to interact with the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) pathway which is required for mature IL-1ß secretion. To understand possible anti-inflammatory properties of FAO inhibition, we tested the effect of pharmacological FAO inhibition using the inhibitor for long-chain 3-ketoacyl coenzyme A thiolase trimetazidine on atherosclerotic plaque development and inflammation. EXPERIMENTAL APPROACH: The effect of FAO inhibition was determined in LDL-R-/- male mice on a C57/BL6 background. In vitro effects of trimetazidine treatment were analyzed in human umbilical vein endothelial cells and human monocyte derived macrophages. KEY RESULTS: We were able to demonstrate that inhibition of FAO reduced atherosclerotic plaque growth. We did not find direct anti-inflammatory properties of trimetazidine in endothelial cells or macrophages in vitro. However, we found that the activation of the NLRP3 system and the secretion of IL-1ß were significantly reduced in macrophages after FAO inhibition. These results were confirmed in atherosclerotic lesions of mice treated with trimetazidine as they showed a significant reduction of IL-1ß and cleaved caspase-1 in the atherosclerotic lesion as well as of IL-1ß and IL-18 in the circulation. CONCLUSION: Overall, we therefore suggest that the main mechanism of reducing inflammation of trimetazidine and FAO inhibition is the reduction of the NLRP-3 activation leading to reduced levels of the proinflammatory cytokine IL-1ß.
Subject(s)
Atherosclerosis/prevention & control , Fatty Acids/metabolism , Macrophages/drug effects , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Receptors, LDL/metabolism , Animals , Cytokines/genetics , Cytokines/metabolism , Gene Expression Regulation/drug effects , Human Umbilical Vein Endothelial Cells , Humans , Inflammasomes/drug effects , Inflammasomes/metabolism , Lipid Metabolism , Macrophages/metabolism , Male , Mice , Mice, Knockout , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Oxidation-Reduction , Receptors, LDL/genetics , Trimetazidine/pharmacology , Vasodilator Agents/pharmacologyABSTRACT
Macrophages are versatile cells that can be polarized by the tissue environment to fulfill required needs. Proinflammatory polarization is associated with increased tissue degradation and propagation of inflammation whereas alternative polarization within a Th2 cytokine environment is associated with wound healing and angiogenesis. To understand if polarization of macrophages can lead to a procoagulant macrophage subset we polarized human monocyte derived macrophages to a proinflammatory and an alternative activation state. Alternative polarization with interleukin-4 and IL-13 led to a macrophage phenotype characterized by increased tissue factor (TF) production and release and by an increase in extracellular vesicle production. In addition, also TF activity was enhanced in extracellular vesicles of alternatively polarized macrophages. This TF induction was dependent on signal transducer and activator of transcription-6 signaling and poly ADP ribose polymerase activity. In contrast to monocytes, human macrophages did not show increased tissue factor expression upon stimulation with lipopolysaccharide and interferon-γ. Previous polarization to either a proinflammatory or an alternative activation subset does not change the subsequent stimulation of TF. The inability of proinflammatory activated macrophages to respond to lipopolysaccharide and interferon-γ with an increase in TF production seems to be due to an increase in TF promoter methylation and was reversible when treating these macrophages with a demethylation agent. In conclusion, we provide evidence that proinflammatory polarization of macrophages does not lead to enhanced procoagulatory function, whereas alternative polarization of macrophages leads to an increased expression of TF and increased production of TF bearing extracellular vesicles by these cells suggesting a procoagulatory phenotype of alternatively polarized macrophages.
Subject(s)
Extracellular Vesicles , Thromboplastin , Cytokines , Humans , Lipopolysaccharides/pharmacology , Macrophages , Thromboplastin/geneticsABSTRACT
The display of native-like human immunodeficiency virus type 1 envelope (HIV-1 Env) trimers on liposomes has gained wide attention over the last few years. Currently, available methods have enabled the preparation of Env-liposome conjugates of unprecedented quality. However, these protocols require the Env trimer to be tagged and/or to carry a specific functional group. For this reason, we have investigated N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide/N-Hydroxysulfosuccinimide (EDC/Sulfo-NHS) chemistry for its potential to covalently conjugate tag-free, non-functionalized native-like Env trimers onto the surface of carboxyl-functionalized liposomes. The preservation of the liposome's physical integrity and the immunogen's conformation required a fine-tuned two-step approach based on the controlled use of ß-mercaptoethanol. The display of Env trimers was strictly limited to activated liposomes of positive charge, i.e., liposomes with a positive zeta potential that carry amine-reactive Sulfo-NHS esters on their surface. In agreement with that, conjugation was found to be highly ionic strength- and pH-dependent. Overall, we have identified electrostatic pre-concentration (i.e., close proximity between negatively charged Env trimers and positively charged liposomes established through electrostatic attraction) to be crucial for conjugation reactions to proceed. The present study highlights the requirements and limitations of potentially scalable EDC/Sulfo-NHS-based approaches and represents a solid basis for further research into the controlled conjugation of tag-free, non-functionalized native-like Env trimers on the surface of liposomes, and other nanoparticles.
ABSTRACT
[This corrects the article DOI: 10.1007/s10049-020-00759-8.].
ABSTRACT
Due to the increasing number of COVID-19 infections worldwide, all hospitals are faced with the challenge associated with the pandemic. In particular, emergency rooms must prepare and implement completely new workflows. This applies in particular to patient screening and selection (triage). Close cooperation with other specialist areas such as hygiene, infectiology or virology is also necessary in order to implement appropriate treatment concepts before, during and after the diagnosis is completed. In addition, communication and quality and risk management are highly relevant in addition to the clinical aspects. This article uses COVID-19 as an example to describe how emergency rooms can prepare for a pandemic.
ABSTRACT
AIMS: Atrial fibrillation (AF) and heart failure (HF) often coexist. Catheter ablation has been reported to restore left ventricular (LV) function but patients benefit differently. This study investigated the correlation between left atrial (LA) fibrosis extent and LV ejection fraction (LVEF) recovery after AF ablation. METHODS AND RESULTS: In this study, 103 patients [64 years, 69% men, 79% persistent AF, LVEF 33% interquartile range (IQR) (25-38)] undergoing first time AF ablation were investigated. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. Continuous rhythm monitoring was used to assess ablation success. Improvement in post-ablation LVEF was measured as primary study endpoint. An absolute increase in post-ablation LVEF ≥10% was defined as 'Super Response'. Left atrial fibrosis was present in 38% of patients. After ablation LVEF increased by absolute 15% (IQR 6-25) (P < 0.001). Left ventricular ejection fraction improvement was higher in patients without LA fibrosis [15% (IQR 10-25) vs. 10% (IQR 0-20), P < 0.001]. An inverse correlation between LVEF improvement and the extent of LA fibrosis was found (R2 = 0.931). In multivariate analysis, the presence of LA fibrosis was the only independent predictor for failing LVEF improvement [odds ratio 7.2 (95% confidence interval 2.2-23.4), P < 0.001]. Echocardiographic 'Super Response' was observed in 55/64 (86%) patients without and 21/39 (54%) patients with LA fibrosis, respectively (P < 0.001). CONCLUSION: Presence and extent of LA fibrosis predict LVEF response in HF patients undergoing AF ablation. The assessment of LA fibrosis may impact prognostic stratification and clinical management in HF patients with AF.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Heart Failure , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Female , Fibrosis , Heart Failure/diagnosis , Humans , Male , Stroke Volume , Treatment Outcome , Ventricular Function, LeftABSTRACT
The MinION sequencer by Oxford Nanopore Technologies turns DNA and RNA sequencing into a routine task in biology laboratories or in field research. For downstream analysis it is required to have a sufficient amount of target reads. Especially prokaryotic or bacteriophagic sequencing samples can contain a significant amount of off-target sequences in the processed sample, stemming from human DNA/RNA contamination, insufficient rRNA depletion, or remaining DNA/RNA from other organisms (e.g. host organism from bacteriophage cultivation). Such impurity, contamination and off-targets (ICOs) block read capacity, requiring to sequence deeper. In comparison to second-generation sequencing, MinION sequencing allows to reuse its chip after a (partial) run. This allows further usage of the same chip with more sample, even after adjusting the library preparation to reduce ICOs. The earlier a sample's ICOs are detected, the better the sequencing chip can be conserved for future use. Here we present sequ-into, a low-resource and user-friendly cross-platform tool to detect ICO sequences from a predefined ICO database in samples early during a MinION sequencing run. The data provided by sequ-into empowers the user to quickly take action to preserve sample material and chip capacity. sequ-into is available from https://github.com/mjoppich/sequ-into.
ABSTRACT
OBJECTIVE: Macrophages are immune cells, capable to remodel the extracellular matrix, which can harbor extracellular DNA incorporated into neutrophil extracellular traps (NETs). To study the breakdown of NETs we studied the capability of macrophage subsets to degrade these structures in vitro and in vivo in a murine thrombosis model. Furthermore, we analyzed human abdominal aortic aneurysm samples in support of our in vitro and in vivo results. Approach and Results: Macrophages were seeded onto blood clots or isolated NETs and polarized. All macrophages were capable to degrade NETs. For initial breakdown, macrophages relied on extracellular deoxyribonucleases. Proinflammatory polarization enhanced NET degradation. The boost in degradation was because of increased macropinocytosis, as inhibition by imipramine diminished their NET breakdown. Inhibition of macropinocytosis in a murine thrombosis model led to increased NET burden and reduced thrombus resolution in vivo. When analyzing abdominal aortic aneurysm samples, macrophage density furthermore corresponded negatively with the amount of local NETs in the intraluminal thrombi as well as in the vessel wall, as increased macrophage density was associated with a reduction in NET burden. CONCLUSIONS: We provide evidence that macrophages degrade NETs by extracellular predigestion and subsequent uptake. Furthermore, we show that proinflammatory macrophages increase NET degradation through enhanced macropinocytosis, priming them for NET engulfment. Based on our findings, that inhibition of macropinocytosis in mice corresponded to increased NET amounts in thrombi and that local macrophage density in human abdominal aortic aneurysm is negatively associated with surrounding NETs, we hypothesize, that macrophages are able to degrade NETs in vivo.
Subject(s)
Endodeoxyribonucleases/metabolism , Extracellular Traps/metabolism , Macrophage Activation , Macrophages/enzymology , Neutrophils/metabolism , Pinocytosis , Animals , Aortic Aneurysm, Abdominal/metabolism , Cells, Cultured , Deoxyribonuclease I/metabolism , Deoxyribonucleases/metabolism , Disease Models, Animal , Exodeoxyribonucleases/metabolism , Female , Humans , Imipramine/pharmacology , Interferon-gamma/pharmacology , Interleukin-13/pharmacology , Interleukin-4/pharmacology , Kinetics , Lipopolysaccharides/pharmacology , Macrophage Activation/drug effects , Macrophages/drug effects , Mice , Mice, Inbred C57BL , Muscle Proteins/metabolism , Phagocytosis , Phenotype , Phosphoproteins/metabolism , Pinocytosis/drug effects , Vena Cava, Inferior/metabolism , Venous Thrombosis/metabolismABSTRACT
BACKGROUND: Left atrial substrate modification targeting low voltage zones (LVZ) is an ablation strategy that-in addition to pulmonary vein (PV) isolation-tries to eliminate arrhythmogenic mechanisms harbored in such tissue. Electrophysiological findings at reablation include (a) PV reconnection, (b) reconnection over previous substrate ablation, and (c) de-novo LVZ. OBJECTIVE: To study, prevalence and contribution of these arrhythmogenic electrophysiological entities in patients with atrial fibrillation (AF) recurrences. METHODS: Consecutive patients with highly symptomatic AF undergoing index and reablation were included (n = 113). In all patients' PV reconnection, reconnection over previous substrate ablation and spontaneous de-novo LVZ were quantitatively assessed and integrated into an individual reablation strategy. Follow-up was based on continuous device monitoring. RESULTS: At re-do procedure, 45 out of 113 (39.8%) patients showed PV reconnection as the only electrophysiological abnormality. Reconduction over previous lines was the only electrophysiological abnormality in 8 out of 113 (7.1%) patients. Spontaneous de-novo LVZ was the only electrophysiological abnormality in 12 out of 113 (10.6%) patients. Combined findings of PV reconnection, line reconduction, and/or spontaneous de-novo LVZ were seen in 40 out of 113 (35.4%) patients. No detectable electrophysiological abnormality was observed in 8 out of 113 (7.1%) patients. In univariate analysis, none of the tested electrophysiological characteristics independently predicted the outcome after re-do. CONCLUSIONS: In patients undergoing reablation, we could show that reconduction over previous substrate ablation as well as the development of new low voltage areas are frequent findings besides classical PV reconnection-without a clear leading cause for recurrences. These findings impact reablation strategies as well as the strategic focus during index procedures.
Subject(s)
Action Potentials , Atrial Fibrillation/surgery , Catheter Ablation , Electrophysiologic Techniques, Cardiac , Heart Rate , Pulmonary Veins/surgery , Aged , Atrial Fibrillation/diagnosis , Atrial Fibrillation/physiopathology , Catheter Ablation/adverse effects , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Pulmonary Veins/physiopathology , Recurrence , Reoperation , Risk Factors , Time Factors , Treatment OutcomeABSTRACT
The objectives of this study were (1) to develop an algorithm for the acceleration sensor of the Smartbow Eartag (Smartbow GmbH, Weibern, Austria) to distinguish between postures (lying and standing or locomotion) and to detect 6 kinds of activities (milk intake, water intake, solid feed intake, ruminating, licking or sucking without milk intake, and other activities) in dairy calves and (2) to evaluate this sensor for identifying these behaviors in dairy calves compared with observations from video. Accelerometers were applied to the left ears of 15 preweaned Holstein dairy calves. Calves were kept in a group pen and received milk replacer from an automatic calf feeder. Based on 38 h of acceleration data and video observation, an algorithm was established to detect the predefined behaviors. Using cross-validation, video recordings were used to analyze whether a behavior was detected correctly by the developed algorithm. For posture, sensitivity (94.4%), specificity (94.3%), precision (95.8%), and accuracy (94.3%) were high. Cohen's kappa was calculated as 0.88. For the 6 defined activities, overall (i.e., aggregated for all activities) accuracy was 70.8% and kappa was calculated as 0.58. Some activities (e.g., ruminating, feed intake, other activities) were identified better than others. In conclusion, the developed algorithm based on the acceleration data of the Smartbow Eartag was successful in detecting lying behavior, rumination, feed intake, and other activities in calves, but further development of the underlying algorithm will be necessary to produce reliable results for milk and water intake.
Subject(s)
Algorithms , Behavior, Animal , Cattle/physiology , Video Recording , Accelerometry/veterinary , Animal Feed , Animals , Diet/veterinary , Digestion , Drinking , Eating , FemaleABSTRACT
Oral mucositis is the most frequently occurring early side effect of head-and-neck cancer radiotherapy. Systemic dermatan sulfate (DS) treatment revealed a significant radioprotective potential in a preclinical model of oral mucositis. This study was initiated to elucidate the mechanistic effects of DS in the same model. Irradiation comprised daily fractionated irradiation (5 × 3 Gy/week) over two weeks, either alone (IR) or in combination with daily dermatan sulfate treatment of 4 mg/kg (IR + DS). Groups of mice (n = 5) were sacrificed every second day over the course of 14 days in both experimental arms, their tongues excised and evaluated. The response to irradiation with and without DS was analyzed on a morphological (cell numbers, epithelial thickness) as well as on a functional (proliferation and expression of inflammation, hypoxia and epithelial junction markers) level. The mucoprotective activity of DS can be attributed to a combination of various effects, comprising increased expression of epithelial junctions, reduced inflammation and reduced hypoxia. No DS-mediated effect on proliferation was observed. DS demonstrated a significant mucositis-ameliorating activity and could provide a promising strategy for mucositis treatment, based on targeting specific, radiation-induced, mucositis-associated signaling without stimulating proliferation.