Ultrafast four-dimensional imaging of cardiac mechanical wave propagation with sparse optoacoustic sensing

2021 ◽  
Vol 118 (45) ◽  
pp. e2103979118
Author(s):  
Çağla Özsoy ◽  
Ali Özbek ◽  
Michael Reiss ◽  
Xosé Luís Deán-Ben ◽  
Daniel Razansky

Propagation of electromechanical waves in excitable heart muscles follows complex spatiotemporal patterns holding the key to understanding life-threatening arrhythmias and other cardiac conditions. Accurate volumetric mapping of cardiac wave propagation is currently hampered by fast heart motion, particularly in small model organisms. Here we demonstrate that ultrafast four-dimensional imaging of cardiac mechanical wave propagation in entire beating murine heart can be accomplished by sparse optoacoustic sensing with high contrast, ∼115-µm spatial and submillisecond temporal resolution. We extract accurate dispersion and phase velocity maps of the cardiac waves and reveal vortex-like patterns associated with mechanical phase singularities that occur during arrhythmic events induced via burst ventricular electric stimulation. The newly introduced cardiac mapping approach is a bold step toward deciphering the complex mechanisms underlying cardiac arrhythmias and enabling precise therapeutic interventions.

Author(s):  
Paulo Victor Sgobbi de Souza ◽  
Bruno de Mattos Lombardi Badia ◽  
Igor Braga Farias ◽  
Eduardo Augusto Gonçalves ◽  
Wladimir Bocca Vieira de Rezende Pinto ◽  
...  

ABSTRACT Background: Acute hepatic porphyrias represent an expanding group of complex inherited metabolic disorders due to inborn errors of metabolism involving heme biosynthesis. Objective: We aimed to review the main clinical and therapeutic aspects associated with acute hepatic porphyrias. Methods: The authors provided a wide non-systematic review of current concepts and recently acquired knowledge about acute hepatic porphyrias. Results: Acute neurovisceral attacks are the most common and life-threatening presentation of this group and are often considered the main clinical manifestation by clinicians during differential diagnosis and the start of proper diagnostic work-up for acute porphyrias. However, atypical presentations with central nervous system involvement, neuropsychiatric disturbances, and some subtypes with photosensitivity usually make the definite diagnosis difficult and late. Early therapeutic interventions are essential during emergency treatment and intercritical periods to avoid recurrent severe presentations. The availability of new disease-modifying therapeutic proposals based on small interfering RNA (siRNA)-based therapies, complementary to the classic intravenous glucose infusion and hemin-based treatments, emphasizes the importance of early diagnosis and genetic counseling of patients. Conclusions: This review article highlights the main biochemical, pathophysiological, clinical, and therapeutic aspects of acute hepatic porphyrias in clinical practice.


2020 ◽  
Vol 21 (12) ◽  
pp. 1250-1263
Author(s):  
Saurabh Shrivastava ◽  
Anshita Gupta ◽  
Chanchal Deep Kaur

Background: Lymphatic filariasis is a pervasive and life-threatening disease for human beings. Currently, 893 million people in 49 countries worldwide affected by lymphatic filariasis as per WHO statistics. The concealed aspects of lymphatic diseases such as delayed disease detection, inappropriate disease imaging, the geographical outbreak of infection, and lack of preventive chemotherapy have brought this epidemic to the edge of Neglected Tropical Diseases. Many medications and natural bioactive substances have seen to promote filaricidal activity against the target parasitic species. However, the majority of failures have occurred in pharmaceutical and pharmacokinetic issues. Objective: The purpose of the study is to focus on the challenges and therapeutic issues in the treatment of filariasis. The review brings novel techniques and therapeutic approaches for combating lymphatic filariasis. It also offers significant developments and opportunities for such therapeutic interventions. Conclusion: Through this review, an attempt has made to critically evaluate the avenues of innovative pharmaceuticals and molecular targeting approaches to bring an integrated solution to combat lymphatic filariasis.


2021 ◽  
Vol 10 (2) ◽  
pp. 366
Author(s):  
Anke Hoffmann ◽  
Dietmar Spengler

Chromodomain Helicase DNA-binding 8 (CHD8) is a high confidence risk factor for autism spectrum disorders (ASDs) and the genetic cause of a distinct neurodevelopmental syndrome with the core symptoms of autism, macrocephaly, and facial dysmorphism. The role of CHD8 is well-characterized at the structural, biochemical, and transcriptional level. By contrast, much less is understood regarding how mutations in CHD8 underpin altered brain function and mental disease. Studies on various model organisms have been proven critical to tackle this challenge. Here, we scrutinize recent advances in this field with a focus on phenotypes in transgenic animal models and highlight key findings on neurodevelopment, neuronal connectivity, neurotransmission, synaptic and homeostatic plasticity, and habituation. Against this backdrop, we further discuss how to improve future animal studies, both in terms of technical issues and with respect to the sex-specific effects of Chd8 mutations for neuronal and higher-systems level function. We also consider outstanding questions in the field including ‘humanized’ mice models, therapeutic interventions, and how the use of pluripotent stem cell-derived cerebral organoids might help to address differences in neurodevelopment trajectories between model organisms and humans.


2005 ◽  
Vol 289 (6) ◽  
pp. H2724-H2732 ◽  
Author(s):  
Xin Zhang ◽  
Indiresha Ramachandra ◽  
Zhongming Liu ◽  
Basharat Muneer ◽  
Steven M. Pogwizd ◽  
...  

Imaging the myocardial activation sequence is critical for improved diagnosis and treatment of life-threatening cardiac arrhythmias. It is desirable to reveal the underlying cardiac electrical activity throughout the three-dimensional (3-D) myocardium (rather than just the endocardial or epicardial surface) from noninvasive body surface potential measurements. A new 3-D electrocardiographic imaging technique (3-DEIT) based on the boundary element method (BEM) and multiobjective nonlinear optimization has been applied to reconstruct the cardiac activation sequences from body surface potential maps. Ultrafast computerized tomography scanning was performed for subsequent construction of the torso and heart models. Experimental studies were then conducted, during left and right ventricular pacing, in which noninvasive assessment of ventricular activation sequence by means of 3-DEIT was performed simultaneously with 3-D intracardiac mapping (up to 200 intramural sites) using specially designed plunge-needle electrodes in closed-chest rabbits. Estimated activation sequences from 3-DEIT were in good agreement with those constructed from simultaneously recorded intracardiac electrograms in the same animals. Averaged over 100 paced beats (from a total of 10 pacing sites), total activation times were comparable (53.3 ± 8.1 vs. 49.8 ± 5.2 ms), the localization error of site of initiation of activation was 5.73 ± 1.77 mm, and the relative error between the estimated and measured activation sequences was 0.32 ± 0.06. The present experimental results demonstrate that the 3-D paced ventricular activation sequence can be reconstructed by using noninvasive multisite body surface electrocardiographic measurements and imaging of heart-torso geometry. This new 3-D electrocardiographic imaging modality has the potential to guide catheter-based ablative interventions for the treatment of life-threatening cardiac arrhythmias.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1260
Author(s):  
Erwan Eriau ◽  
Juliette Paillet ◽  
Guido Kroemer ◽  
Jonathan G. Pol

Caloric restriction and fasting have been known for a long time for their health- and life-span promoting effects, with coherent observations in multiple model organisms as well as epidemiological and clinical studies. This holds particularly true for cancer. The health-promoting effects of caloric restriction and fasting are mediated at least partly through their cellular effects—chiefly autophagy induction—rather than reduced calorie intake per se. Interestingly, caloric restriction has a differential impact on cancer and healthy cells, due to the atypical metabolic profile of malignant tumors. Caloric restriction mimetics are non-toxic compounds able to mimic the biochemical and physiological effects of caloric restriction including autophagy induction. Caloric restriction and its mimetics induce autophagy to improve the efficacy of some cancer treatments that induce immunogenic cell death (ICD), a type of cellular demise that eventually elicits adaptive antitumor immunity. Caloric restriction and its mimetics also enhance the therapeutic efficacy of chemo-immunotherapies combining ICD-inducing agents with immune checkpoint inhibitors targeting PD-1. Collectively, preclinical data encourage the application of caloric restriction and its mimetics as an adjuvant to immunotherapies. This recommendation is subject to confirmation in additional experimental settings and in clinical trials. In this work, we review the preclinical and clinical evidence in favor of such therapeutic interventions before listing ongoing clinical trials that will shed some light on this subject.


Author(s):  
Michele Mussap ◽  
Vassilios Fanos

Abstract Human Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection activates a complex interaction host/virus, leading to the reprogramming of the host metabolism aimed at the energy supply for viral replication. Alterations of the host metabolic homeostasis strongly influence the immune response to SARS-CoV-2, forming the basis of a wide range of outcomes, from the asymptomatic infection to the onset of COVID-19 and up to life-threatening acute respiratory distress syndrome, vascular dysfunction, multiple organ failure, and death. Deciphering the molecular mechanisms associated with the individual susceptibility to SARS-CoV-2 infection calls for a system biology approach; this strategy can address multiple goals, including which patients will respond effectively to the therapeutic treatment. The power of metabolomics lies in the ability to recognize endogenous and exogenous metabolites within a biological sample, measuring their concentration, and identifying perturbations of biochemical pathways associated with qualitative and quantitative metabolic changes. Over the last year, a limited number of metabolomics- and lipidomics-based clinical studies in COVID-19 patients have been published and are discussed in this review. Remarkable alterations in the lipid and amino acid metabolism depict the molecular phenotype of subjects infected by SARS-CoV-2; notably, structural and functional data on the lipids-virus interaction may open new perspectives on targeted therapeutic interventions. Several limitations affect most metabolomics-based studies, slowing the routine application of metabolomics. However, moving metabolomics from bench to bedside cannot imply the mere determination of a given metabolite panel; rather, slotting metabolomics into clinical practice requires the conversion of metabolic patient-specific data into actionable clinical applications.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3135-3135
Author(s):  
Yan Leyfman ◽  
Nancy Emmanuel ◽  
Aleksey Tentler ◽  
Jared Cappelli ◽  
Timothy K Erick ◽  
...  

3135 Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel betacoronavirus that causes the respiratory illness coronavirus disease 2019 (COVID-19). COVID-19 ranges in severity from an asymptomatic viral infection to life-threatening cases of pneumonia, acute respiratory distress syndrome (ARDS), multi-organ damage and sepsis. Cancer patients are at an increased risk of severe SARS-CoV-2 infection due to their immunocompromised status. We propose a mechanism by which SARS-CoV-2 infection causes multiple organ damage through IL-6-mediated inflammation and hypoxia-induced cellular metabolic alterations leading to cell death. Hypoxia is also induced by malignancy due to alterations in metabolism, resulting in greater IL-6 secretion. Methods: To highlight the possible effect of active cancer on the likelihood of hypoxia in COVID-19, we analyzed the correlation between cancer status and the severity of COVID-19 from the COVID-19 and Cancer Consortium data registry. For cancer status, we looked at progressive cancer and remission of cancer only -- those being the two extremes of presence and absence of uncontrolled cancer. Similar to prior studies, the severity of COVID-19 was used as an indication of hypoxia. Results: We observed a 24% positive deviation between expected and actual number of patients with actively progressing cancer who had hypoxic COVID-19 (moderate to severe), and a 26.9% negative deviation between expected and actual number of patients with active cancer who had no hypoxia with COVID-19 (p<0.0001). Conversely, for patients with cancer in remission, there was only a +5.8% and -5.1% deviation between expected and actual number of patients who did not have hypoxia and who had hypoxia, respectively. Conclusions: These results suggest that in the presence of poorly controlled malignancy, there is an increased likelihood of hypoxia in patients with COVID-19, thereby exacerbating downstream cytokine release syndrome and contributing to prolonged systemic inflammatory injury. Appreciating this pathway, future therapies can be developed to target the pathogenesis of both diseases and prevent progression, as seen with mesenchymal stem cells, which demonstrated a 91% overall survival and 100% survival in patients younger than 85 years old at one month after a single treatment.[Table: see text]


2020 ◽  
Author(s):  
Jennifer E. Hewitt ◽  
Ricardo Laranjeiro ◽  
Masoud Norouzi ◽  
Rebecca Ellwood ◽  
Adam Antebi ◽  
...  

ABSTRACTDetermining the physical performance of humans using several measures is essential to evaluating the severity of diseases, understanding the role of environmental factors, and developing therapeutic interventions. Development of analogous measures of physical performance in model organisms can help in identifying conserved signaling pathways and prioritizing drug candidates. In this study, we propose a multi-environment phenotyping (MEP) approach that generates a comprehensive set of measures indicative of physical performance in C. elegans. We challenge C. elegans in different mechanical environments of burrowing, swimming, and crawling, each of which places different physiological demands on the animals to generate locomotory forces. Implementation of the MEP approach is done using three established assays corresponding to each environment–a hydrogel-based burrowing assay, the CeleST swim assay, and the NemaFlex crawling strength assay. Using this approach, we study individuals and show that these three assays report on unique aspects of nematode physiology, as phenotypic measures obtained from different environments do not correlate with one another. Analysis of a subset of genes representative of oxidative stress, glucose metabolism, and fat metabolism show differential expression depending on the animal’s environment, suggesting that each environment evokes a response with distinct genetic requirements. To demonstrate the utility of the MEP platform, we evaluate the response of a muscular dystrophy model of C. elegans dys-1 to drug interventions of prednisone, melatonin and serotonin. We find that prednisone, which is the current treatment standard for human Duchenne muscular dystrophy, confers benefits in all three assays. Furthermore, while the tested compounds improve the physical performance of dys-1, these compounds are not able to fully restore the measures to wild-type levels, suggesting the need for discovery efforts to identify more efficacious compounds that could be aided using the MEP platform. In summary, the MEP platform’s ability to robustly define C. elegans locomotory phenotypes demonstrates the utility of the MEP approach toward identification of candidates for therapeutic intervention, especially in disease models in which the neuromuscular performance is impaired.


2019 ◽  
Vol 5 (1 (P)) ◽  
pp. 12
Author(s):  
Dicky Armein Hanafy

Sudden cardiac death is one of the leading causes of death in the western industrial nations. Most people are affected by coronary heart disease (coronary heart disease, CHD) or heart muscle (cardiomyopathy). These can lead to life-threatening cardiac arrhythmias. If the heartbeat is too slow due to impulse or conduction disturbances, cardiac pacemakers will be implanted. High-frequency and life-threatening arrhythmias of the ventricles (ventricular tachycardia, flutter or fibrillation) cannot be treated with a pacemaker. In such cases, an implantable cardioverter-defibrillator (ICD) is used, which additionally also provides all functions of a pacemaker. The implantation of a defibrillator is appropriate if a high risk of malignant arrhythmias has been established (primary prevention). If these life-threatening cardiac arrhythmias have occurred before and are not caused by a treatable (reversible) cause, ICD implantation will be used for secondary prevention. The device can stop these life-threatening cardiac arrhythmias by delivering a shock or rapid impulse delivery (antitachycardic pacing) to prevent sudden cardiac death. Another area of application for ICD therapy is advanced heart failure (heart failure), in which both main chambers and / or different wall sections of the left ventricle no longer work synchronously. This form of cardiac insufficiency can be treated by electrical stimulation (cardiac resynchronization therapy, CRT). Since the affected patients are also at increased risk for sudden cardiac death, combination devices are usually implanted, which combine heart failure treatment by resynchronization therapy and the prevention of sudden cardiac death by life-threatening arrhythmia of the heart chambers (CRT-D device). An ICD is implanted subcutaneously or under the pectoral muscle in the area of the left collarbone. Like pacemaker implantation, ICD implantation is a routine, low-complication procedure today.


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