31 research outputs found
Boundary-interior principle for microbial navigation in geometric confinement
When the motion of a motile cell is observed closely, it appears erratic, and
yet the combination of nonequilibrium forces and surfaces can produce striking
examples of collective organization in microbial systems. While our current
understanding is based on bulk systems or idealized geometries, it is not clear
at which length scale self-organization emerges. Here, using experiments,
analytical and numerical calculations we study the motion of motile cells under
controlled microfluidic conditions, and demonstrate that a robust topology of
probability flux loops organizes active motion even at the level of a single
cell exploring an isolated habitat. By accounting for the interplay of activity
and interfacial forces, we find that the boundary's curvature determines the
nonequilibrium probability fluxes of the motion, which can be controlled
directly. We theoretically predict a universal relation between fluxes and
global geometric properties that is directly confirmed by experiments. Our
findings open the possibility to decipher the most probable trajectories of
motile cells and may enable the design of active topological materials
Clinical correlates and prognostic impact of neurologic disorders in Takotsubo syndrome
Cardiac alterations are frequently observed after acute neurological disorders. Takotsubo syndrome (TTS) represents an acute heart failure syndrome and is increasingly recognized as part of the spectrum of cardiac complications observed after neurological disorders. A systematic investigation of TTS patients with neurological disorders has not been conducted yet. The aim of the study was to expand insights regarding neurological disease entities triggering TTS and to investigate the clinical profile and outcomes of TTS patients after primary neurological disorders. The International Takotsubo Registry is an observational multicenter collaborative effort of 45 centers in 14 countries (ClinicalTrials.gov, identifier NCT01947621). All patients in the registry fulfilled International Takotsubo Diagnostic Criteria. For the present study, patients were included if complete information on acute neurological disorders were available. 2402 patients in whom complete information on acute neurological status were available were analyzed. In 161 patients (6.7%) an acute neurological disorder was identified as the preceding triggering factor. The most common neurological disorders were seizures, intracranial hemorrhage, and ischemic stroke. Time from neurological symptoms to TTS diagnosis was <= 2 days in 87.3% of cases. TTS patients with neurological disorders were younger, had a lower female predominance, fewer cardiac symptoms, lower left ventricular ejection fraction, and higher levels of cardiac biomarkers. TTS patients with neurological disorders had a 3.2-fold increased odds of in-hospital mortality compared to TTS patients without neurological disorders. In this large-scale study, 1 out of 15 TTS patients had an acute neurological condition as the underlying triggering factor. Our data emphasize that a wide spectrum of neurological diseases ranging from benign to life-threatening encompass TTS. The high rates of adverse events highlight the need for clinical awareness
Clinical correlates and prognostic impact of neurologic disorders in Takotsubo syndrome
© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Cardiac alterations are frequently observed after acute neurological disorders. Takotsubo syndrome (TTS) represents an acute heart failure syndrome and is increasingly recognized as part of the spectrum of cardiac complications observed after neurological disorders. A systematic investigation of TTS patients with neurological disorders has not been conducted yet. The aim of the study was to expand insights regarding neurological disease entities triggering TTS and to investigate the clinical profile and outcomes of TTS patients after primary neurological disorders. The International Takotsubo Registry is an observational multicenter collaborative effort of 45 centers in 14 countries (ClinicalTrials.gov, identifier NCT01947621). All patients in the registry fulfilled International Takotsubo Diagnostic Criteria. For the present study, patients were included if complete information on acute neurological disorders were available. 2402 patients in whom complete information on acute neurological status were available were analyzed. In 161 patients (6.7%) an acute neurological disorder was identified as the preceding triggering factor. The most common neurological disorders were seizures, intracranial hemorrhage, and ischemic stroke. Time from neurological symptoms to TTS diagnosis was ≤ 2 days in 87.3% of cases. TTS patients with neurological disorders were younger, had a lower female predominance, fewer cardiac symptoms, lower left ventricular ejection fraction, and higher levels of cardiac biomarkers. TTS patients with neurological disorders had a 3.2-fold increased odds of in-hospital mortality compared to TTS patients without neurological disorders. In this large-scale study, 1 out of 15 TTS patients had an acute neurological condition as the underlying triggering factor. Our data emphasize that a wide spectrum of neurological diseases ranging from benign to life-threatening encompass TTS. The high rates of adverse events highlight the need for clinical awareness.The International Takotsubo Registry was supported by the Biss Davies Charitable Trust. Dr. Scheitz has been supported by the Corona Foundation. Dr. Templin has been supported by the H.H. Sheikh Khalifa bin Hamad Al-Thani Research Programme and the Swiss Heart Foundation.info:eu-repo/semantics/publishedVersio
Prognostic impact of acute pulmonary triggers in patients with Takotsubo syndrome : new insights from the International Takotsubo Registry
© 2021 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License.Aims: Acute pulmonary disorders are known physical triggers of takotsubo syndrome (TTS). This study aimed to investigate prevalence of acute pulmonary triggers in patients with TTS and their impact on outcomes.
Methods and results: Patients with TTS were enrolled from the International Takotsubo Registry and screened for triggering factors and comorbidities. Patients were categorized into three groups (acute pulmonary trigger, chronic lung disease, and no lung disease) to compare clinical characteristics and outcomes. Of the 1670 included patients with TTS, 123 (7%) were identified with an acute pulmonary trigger, and 194 (12%) had a known history of chronic lung disease. The incidence of cardiogenic shock was highest in patients with an acute pulmonary trigger compared with those with chronic lung disease or without lung disease (17% vs. 10% vs. 9%, P = 0.017). In-hospital mortality was also higher in patients with an acute pulmonary trigger than in the other two groups, although not significantly (5.7% vs. 1.5% vs. 4.2%, P = 0.13). Survival analysis demonstrated that patients with an acute pulmonary trigger had the worst long-term outcome (P = 0.002). The presence of an acute pulmonary trigger was independently associated with worse long-term mortality (hazard ratio 2.12, 95% confidence interval 1.33-3.38; P = 0.002).
Conclusions: The present study demonstrates that TTS is related to acute pulmonary triggers in 7% of all TTS patients, which accounts for 21% of patients with physical triggers. The presence of acute pulmonary trigger is associated with a severe in-hospital course and a worse long-term outcome.C. T. has been supported by the H.H. Sheikh Khalifa binHamad Al-Thani Research Programme and the Swiss HeartFoundation. The InterTAK Registry is supported by the BissDavies Charitable Trust. L. S. M. has been supported by EUHORIZON 2020(SILICOFCM ID777204)info:eu-repo/semantics/publishedVersio
Ethnic comparison in takotsubo syndrome : novel insights from the International Takotsubo Registry
© The Author(s) 2021. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Background: Ethnic disparities have been reported in cardiovascular disease. However, ethnic disparities in takotsubo syndrome (TTS) remain elusive. This study assessed differences in clinical characteristics between Japanese and European TTS patients and determined the impact of ethnicity on in-hospital outcomes.
Methods: TTS patients in Japan were enrolled from 10 hospitals and TTS patients in Europe were enrolled from 32 hospitals participating in the International Takotsubo Registry. Clinical characteristics and in-hospital outcomes were compared between Japanese and European patients.
Results: A total of 503 Japanese and 1670 European patients were included. Japanese patients were older (72.6 ± 11.4 years vs. 68.0 ± 12.0 years; p < 0.001) and more likely to be male (18.5 vs. 8.4%; p < 0.001) than European TTS patients. Physical triggering factors were more common (45.5 vs. 32.0%; p < 0.001), and emotional triggers less common (17.5 vs. 31.5%; p < 0.001), in Japanese patients than in European patients. Japanese patients were more likely to experience cardiogenic shock during the acute phase (15.5 vs. 9.0%; p < 0.001) and had a higher in-hospital mortality (8.2 vs. 3.2%; p < 0.001). However, ethnicity itself did not appear to have an impact on in-hospital mortality. Machine learning approach revealed that the presence of physical stressors was the most important prognostic factor in both Japanese and European TTS patients.
Conclusion: Differences in clinical characteristics and in-hospital outcomes between Japanese and European TTS patients exist. Ethnicity does not impact the outcome in TTS patients. The worse in-hospital outcome in Japanese patients, is mainly driven by the higher prevalence of physical triggers.Open Access funding provided by Universität Zürich. CT has been supported by the H.H. Sheikh Khalifa bin Hamad Al-Thani Research Programme and the Swiss Heart Foundation. L.S.M. has been supported by EU HORIZON 2020 (SILICOFCM ID777204). J.R.G has received a grant “Filling the gap” from the University of Zurich. The InterTAK Registry is supported by The Biss Davies Charitable Trust.info:eu-repo/semantics/publishedVersio
Clinical Predictors and Prognostic Impact of Recovery of Wall Motion Abnormalities in Takotsubo Syndrome: Results From the International Takotsubo Registry
Background-Left ventricular (LV) recovery in takotsubo syndrome (TTS) occurs over a wide-ranging interval, varying from hours to weeks. We sought to investigate the clinical predictors and prognostic impact of recovery time for TTS patients.Methods and Results-TTS patients from the International Takotsubo Registry were included in this study. Cut-off for early LV recovery was determined to be 10 days after the acute event. Multivariable logistic regression was used to assess factors associated with the absence of early recovery. In-hospital outcomes and 1-year mortality were compared for patients with versus without early recovery. We analyzed 406 patients with comprehensive and serial imaging data regarding time to recovery. Of these, 191 (47.0%) had early LV recovery and 215 (53.0%) demonstrated late LV improvement. Patients without early recovery were more often male (12.6% versus 5.2%; P=0.011) and presented more frequently with typical TTS (76.3% versus 67.0%, P=0.040). Cardiac and inflammatory markers were higher in patients without early recovery than in those with early recovery. Patients without early recovery showed unfavorable 1-year outcome compared with patients with early recovery (P=0.003). On multiple logistic regression, male sex, LV ejection fraction <45%, and acute neurologic disorders were associated with the absence of early recovery.Conclusions-TTS patients without early LV recovery have different clinical characteristics and less favorable 1-year outcome compared with patients with early recovery. The factors associated with the absence of early recovery included male sex, reduced LV ejection fraction, and acute neurologic events
Ethnic comparison in takotsubo syndrome: novel insights from the International Takotsubo Registry
Background Ethnic disparities have been reported in cardiovascular disease. However, ethnic disparities in takotsubo syndrome (TTS) remain elusive. This study assessed differences in clinical characteristics between Japanese and European TTS patients and determined the impact of ethnicity on in-hospital outcomes.Methods TTS patients in Japan were enrolled from 10 hospitals and TTS patients in Europe were enrolled from 32 hospitals participating in the International Takotsubo Registry. Clinical characteristics and in-hospital outcomes were compared between Japanese and European patients.Results A total of 503 Japanese and 1670 European patients were included. Japanese patients were older (72.6 +/- 11.4 years vs. 68.0 +/- 12.0 years; p Conclusion Differences in clinical characteristics and in-hospital outcomes between Japanese and European TTS patients exist. Ethnicity does not impact the outcome in TTS patients. The worse in-hospital outcome in Japanese patients, is mainly driven by the higher prevalence of physical triggers.</p
Mathematical modelling of microbial motility
Microbial life pervades our planet, and many species evolved the ability to propel themselves in their quest to colonise new environments. Understanding their movement patterns may have far-reaching implications such as the possibility of harnessing their motility to power microscopic machines, or using them to transport and mix microscopic cargo. Such insight will also shed light on crucial ecological processes, like the distribution of algae in the ocean or devise strategies to either accelerate or stop the colonisation of surfaces by all kinds of microorganisms.This thesis aims to advance the field of the physical and mathematical understanding of microbial motility by developing comprehensive models that incorporate both physical and biological factors to explore the behaviour of different classes of microorganisms. Existing models are refined, new ones developed, and new techniques are applied to analyse their behaviour.Within the scope of this thesis, models for three distinct systems are developed and meticulously analysed. Firstly, the behaviour of an isolated microswimmer in complex confinement is explored. We leverage tools of nonequilibrium physics to build a description of microbial motility based on probability flux loops uncovering patterns hidden in the system. A comprehensive comparison between model predictions and experimental observations confirms a quantitative agreement in the emerging fluxes. Secondly, we investigate the collective self-organisation of filamentous cyanobacteria that adhere to surfaces and frequently glide over one another. This behaviour enables pattern formation not observed in other classes of active matter. A novel approach to describe this kind of motion is introduced and their collective dynamics are explored. Comparisons with experiments reveal an intriguing connection between the properties of individual filaments and emerging structures. We predict that the balance of active motion and curvature fluctuations determines the length scale of the pattern. Lastly, motivated by the “paradox of the plankton”, that questions how many species of phytoplankton can seemingly occupy the same ecological niche, a model for phytoplankton in oceanic turbulence is devised, coupling the motion and interactions of active particles to a turbulent field.Through the application of fundamental physical principles, and by the development, refinement, and analysis of these models, this thesis aims to expand our understanding of microbial motility, shedding light on fundamental aspects of microbial behaviour in diverse environments. The findings presented in this work may have implications for applications ranging from designing motility-powered microscopic devices to unravelling ecological processes in marine ecosystems.</p
Erhöhte Empfindlichkeit und Reproduzierbarkeit durch Signal-Mittelwertrechnung in Bereichen nahe einer instrumentellen Nachweisgrenze
Active spaghetti: collective organization in cyanobacteria
Filamentous cyanobacteria can show fascinating patterns of nonequilibrium self-organization, which however are not well-understood from a physical perspective. We investigate the motility and collective organization of colonies of these simple multicellular lifeforms. As their area density increases, linear chains of cells gliding on a substrate show a transition from an isotropic distribution to bundles of filaments arranged in a reticulate pattern. Based on our experimental observations of individual behavior and pairwise interactions, we introduce a model accounting for the filaments’ large aspect ratio, fluctuations in curvature, motility, and nematic interactions. This minimal model of active filaments recapitulates the observations, and rationalizes the appearance of a characteristic lengthscale in the system, based on the Péclet number of the cyanobacteria filaments.</p