1,720,981 research outputs found
Human versus porcine tissue sourcing for an injectable myocardial matrix hydrogel
No full textHeart failure (HF) after myocardial infarction (MI) is a leading cause of death in the western world with a critical need for new therapies. A previously developed injectable hydrogel derived from porcine myocardial matrix (PMM) has had successful results in both small and large animal MI models. In this study, we sought to evaluate the impact of tissue source on this biomaterial, specifically comparing porcine and human myocardium sources. We first developed an analogous hydrogel derived from human myocardial matrix (HMM). The biochemical and physical properties of the PMM and HMM hydrogels were then characterized, including residual dsDNA, protein content, sulfated glycosaminoglycan (sGAG) content, complex viscosity, storage and loss moduli, and nano-scale topography. Biochemical activity was investigated with in vitro studies for the proliferation of vascular cells and differentiation of human cardiomyocyte progenitor cells (hCMPCs). Next, in vivo gelation and material spread were confirmed for both PMM and HMM after intramyocardial injection. After extensive comparison, the matrices were found to be similar, yet did show some differences. Because of the rarity of collecting healthy human hearts, the increased difficulty in processing the human tissue, shifts in extracellular matrix (ECM) composition due to aging, and significant patient-to-patient variability, these studies suggest that the HMM is not a viable option as a scalable product for the clinic; however, the HMM has potential as a tool for in vitro cell culture
Cell Therapy Improves Quality-of-Life in Heart Failure: Outcomes From a Phase III Clinical Trial
No full text: Patients with heart failure experience limitations in daily activity and poor quality-of-life. Prospective surveillance of health-related quality-of-life supplemented traditional death and hospitalization outcomes in the multinational, randomized, double-blinded CHART-1 clinical trial that assessed cardiopoiesis-guided cell therapy in ischemic heart failure patients with reduced left ventricular ejection fraction. The Minnesota Living with Heart Failure Questionnaire (MLHFQ), a Food and Drug Administration qualified instrument for evaluating therapeutic effectiveness, was applied through the 1-year follow-up. Cell treated (n = 109) and sham procedure (n = 140) cohorts reported improved MLHFQ scores comparable between the 2 study arms (mean treatment difference with baseline adjustment -3.2 points, P = .107). Superiority of cell treatment over sham in betterment of the MLHFQ score was demonstrated in patients with pre-existing advanced left ventricular enlargement (baseline-adjusted mean treatment difference -6.4 points, P = .009). In this highly responsive subpopulation, benefit on the MLHFQ score paralleled reduction in death and hospitalization post-cell therapy (adjusted Mann-Whitney odds 1.43, 95% CI, 1.01-2.01; P = .039). The potential of cell therapy in addressing the quality-of-life dimension of heart failure requires further evaluation for disease relief
Endpoints in stem cell trials in ischemic heart failure
No full textDespite multimodal regimens and diverse treatment options alleviating disease symptoms, morbidity and mortality associated with advanced ischemic heart failure remain high. Recently, technological innovation has led to the development of regenerative therapeutic interventions aimed at halting or reversing the vicious cycle of heart failure progression. Driven by the unmet patient need and fueled by encouraging experimental studies, stem cell-based clinical trials have been launched over the past decade. Collectively, these trials have enrolled several thousand patients and demonstrated the clinical feasibility and safety of cell-based interventions. However, the totality of evidence supporting their efficacy in ischemic heart failure remains limited. Experience from the early randomized stem cell clinical trials underscores the key points in trial design ranging from adequate hypothesis formulation to selection of the optimal patient population, cell type and delivery route. Importantly, to translate the unprecedented promise of regenerative biotherapies into clinical benefit, it is crucial to ensure the appropriate choice of endpoints along the regulatory path. Accordingly, we here provide considerations relevant to the choice of endpoints for regenerative clinical trials in the ischemic heart failure setting
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Stem cell therapy for heart failure: Ensuring regenerative proficiency
No full textAbstractPatient-derived stem cells enable promising regenerative strategies, but display heterogenous cardiac reparative proficiency, leading to unpredictable therapeutic outcomes impeding practice adoption. Means to establish and certify the regenerative potency of emerging biotherapies are thus warranted. In this era of clinomics, deconvolution of variant cytoreparative performance in clinical trials offers an unprecedented opportunity to map pathways that segregate regenerative from non-regenerative states informing the evolution of cardio-regenerative quality systems. A maiden example of this approach is cardiopoiesis-mediated lineage specification developed to ensure regenerative performance. Successfully tested in pre-clinical and early clinical studies, the safety and efficacy of the cardiopoietic stem cell phenotype is undergoing validation in pivotal trials for chronic ischemic cardiomyopathy offering the prospect of a next-generation regenerative solution for heart failure
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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