Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Dual-sided Mapping During Global Stretch Using a Custom Miniaturized Endocardial Balloon with a Multipurpose Multichannel Acquisition System for Prec…
2017
Acute regional myocardial stretch (STR) is known to induce myocardial electrophysiological modifications via mechano-electric feedback (MEF), including abnormal repolarization, premature excitation and increased complexity of activation leading to the initiation, maintenance and acceleration of arrhythmic events. Due to technical limitations little is known about intramural and endo-epicardial (ENDO-EPI) phenomena during these events. Understanding ENDO-EPI modifications produced by STR through MEF may require a dual-sided approach to simultaneously correlate macroscopic surface modifications and their independent or interconnected components. For that purpose, we optically mapped (OM) the …
A Natural Xenogeneic Endometrial Extracellular Matrix Hydrogel Toward Improving Current Human in vitro Models and Future in vivo Applications
2021
Decellularization techniques support the creation of biocompatible extracellular matrix hydrogels, providing tissue-specific environments for both in vitro cell culture and in vivo tissue regeneration. We obtained endometrium derived from porcine decellularized uteri to create endometrial extracellular matrix (EndoECM) hydrogels. After decellularization and detergent removal, we investigated the physicochemical features of the EndoECM, including gelation kinetics, ultrastructure, and proteomic profile. The matrisome showed conservation of structural and tissue-specific components with low amounts of immunoreactive molecules. EndoECM supported in vitro culture of human endometrial cells in t…
In vivo muscle morphology comparison in post-stroke survivors using ultrasonography and diffusion tensor imaging.
2019
AbstractSkeletal muscle architecture significantly influences the performance capacity of a muscle. A DTI-based method has been recently considered as a new reference standard to validate measurement of muscle structure in vivo. This study sought to quantify muscle architecture parameters such as fascicle length (FL), pennation angle (PA) and muscle thickness (tm) in post-stroke patients using diffusion tensor imaging (DTI) and to quantitatively compare the differences with 2D ultrasonography (US) and DTI. Muscle fascicles were reconstructed to examine the anatomy of the medial gastrocnemius, posterior soleus and tibialis anterior in seven stroke survivors using US- and DTI-based techniques…
In Vivo Functional Evaluation of Tissue-Engineered Vascular Grafts Fabricated Using Human Adipose-Derived Stem Cells from High Cardiovascular Risk Po…
2016
Many preclinical evaluations of autologous small-diameter tissue-engineered vascular grafts (TEVGs) utilize cells from healthy humans or animals. However, these models hold minimal relevance for clinical translation, as the main targeted demographic is patients at high cardiovascular risk such as individuals with diabetes mellitus or the elderly. Stem cells such as adipose-derived mesenchymal stem cells (AD-MSCs) represent a clinically ideal cell type for TEVGs, as these can be easily and plentifully harvested and offer regenerative potential. To understand whether AD-MSCs sourced from diabetic and elderly donors are as effective as those from young nondiabetics (i.e., healthy) in the conte…
Effects of Study Population, Labeling and Training on Glaucoma Detection Using Deep Learning Algorithms
2020
Author(s): Christopher, Mark; Nakahara, Kenichi; Bowd, Christopher; Proudfoot, James A; Belghith, Akram; Goldbaum, Michael H; Rezapour, Jasmin; Weinreb, Robert N; Fazio, Massimo A; Girkin, Christopher A; Liebmann, Jeffrey M; De Moraes, Gustavo; Murata, Hiroshi; Tokumo, Kana; Shibata, Naoto; Fujino, Yuri; Matsuura, Masato; Kiuchi, Yoshiaki; Tanito, Masaki; Asaoka, Ryo; Zangwill, Linda M | Abstract: PurposeTo compare performance of independently developed deep learning algorithms for detecting glaucoma from fundus photographs and to evaluate strategies for incorporating new data into models.MethodsTwo fundus photograph datasets from the Diagnostic Innovations in Glaucoma Study/African Descent…
Time-kill assays of amphotericin B plus anidulafungin against Candida tropicalis biofilms formed on two different biomaterials.
2017
Purpose: To determine the fungicidal activity by time-killing assays of amphotericin B (AMB) combined with anidulafungin (ANF) against biofilms of 2 clinical isolates of Candida tropicalis and the reference strain ATCC® 750, developed on polytetrafluoroethylene (PTFE) and titanium, using the CDC Biofilm Reactor (CBR) as an in vitro model. Methods: Biofilms were developed for 24 hours on the disk surfaces and then exposed to AMB (40 mg/L), ANF (8 mg/L), alone and combined. At predetermined time points after drug exposure, biofilms were removed from the disk surface by vortexing-sonication to quantify viable biofilm cells. Results: Drug activity was dependent on strain and time. After exposur…
Culture into perfusion-assisted bioreactor promotes valve-like tissue maturation of recellularized pericardial membrane
2020
Derivation of tissue-engineered valve replacements is a strategy to overcome the limitations of the current valve prostheses, mechanical, or biological. In an effort to set living pericardial material for aortic valve reconstruction, we have previously assessed the efficiency of a recellularization strategy based on a perfusion system enabling mass transport and homogenous distribution of aortic valve-derived “interstitial” cells inside decellularized pericardial material. In the present report, we show that alternate perfusion promoted a rapid growth of valve cells inside the pericardial material and the activity of a proliferation-supporting pathway, likely controlled by the YAP transcrip…
Risk Assessment of Hip Fracture Based on Machine Learning
2020
[EN] Identifying patients with high risk of hip fracture is a great challenge in osteoporosis clinical assessment. Bone Mineral Density (BMD) measured by Dual-Energy X-Ray Absorptiometry (DXA) is the current gold standard in osteoporosis clinical assessment. However, its classification accuracy is only around 65%. In order to improve this accuracy, this paper proposes the use of Machine Learning (ML) models trained with data from a biomechanical model that simulates a sideways-fall. Machine Learning (ML) models are models able to learn and to make predictions from data. During a training process, ML models learn a function that maps inputs and outputs without previous knowledge of the probl…
AMD3100: A Versatile Platform for CXCR4 Targeting 68 Ga-Based Radiopharmaceuticals
2016
International audience; CXCR4 is a G protein-coupled receptor (GPCR), which is overexpressed in numerous diseases, particularly in multiple cancers. Therefore, this receptor represents a valuable target for imaging and therapeutic purposes. Among the different approaches, which were developed for CXCR4 imaging, a CXCR4 antagonist biscyclam system (AMD3100, also called Mozobil), currently used in the clinic for the mobilization of hematopoietic stem cells, was radiolabeled with different radiometals such as 62Zn, 64Cu, 67Ga, or 99mTc. However, cyclam is not an ideal chelator for most of these radiometals, and could lead to the release of the radionuclide in vivo. In the current study, a new …
Dextran-based therapeutic nanoparticles for hepatic drug delivery.
2016
Aim: Evaluation of dextran-based nanoparticles (DNP) as a drug delivery system to target myeloid cells of the liver. Materials & methods: DNP were synthesized and optionally PEGylated. Their toxicity and cellular uptake were studied in vitro. Empty and siRNA-carrying DNP were tested in vivo with regard to biodistribution and cellular uptake. Results: In vitro, DNP were taken up by cells of the myeloid lineage without compromising their viability. In vivo, empty and siRNA-carrying DNP distributed to the liver where a single treatment addressed approximately 70% of macrophages and dendritic cells. Serum parameters indicated no in vivo toxicity. Conclusion: DNP are multifunctional liver-s…