scholarly journals Non-invasive multimodal imaging techniques for in vivo characterization of electrical dyssynchrony in large animal models: feasibility study

2017 ◽  
Vol 9 (2) ◽  
pp. 166-167
Author(s):  
C. Carlos Sampedrano ◽  
S. Ploux ◽  
L. Bear ◽  
P. Bour ◽  
M. Strick ◽  
...  
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Sally A. Boxall ◽  
Elena Jones

Given the observed efficacy of culture-expanded multipotential stromal cells, also termed mesenchymal stem cells (MSCs), in the treatment of graft-versus host and cardiac disease, it remains surprising that purity and potency characterization of manufactured cell batches remains rather basic. In this paper, we will initially discuss surface and molecular markers that were proposed to serve as the indicators of the MSC potency, in terms of their proliferative potential or the ability to differentiate into desired lineages. The second part of this paper will be dedicated to a critical discussion of surface markers of uncultured (i.e., native) bone marrow (BM) MSCs. Although no formal consensus has yet been reached on which markers may be best suited for prospective BM MSC isolation, markers that cross-react with MSCs of animal models (such as CD271 and W8-B2/MSCA-1) may have the strongest translational value. Whereas small animal models are needed to discover thein vivofunction on these markers, large animal models are required for safety and efficacy testing of isolated MSCs, particularly in the field of bone and cartilage tissue engineering.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 713
Author(s):  
Shu Fang ◽  
Ditte Gry Ellman ◽  
Ditte Caroline Andersen

To date, a wide range of materials, from synthetic to natural or a mixture of these, has been explored, modified, and examined as small-diameter tissue-engineered vascular grafts (SD-TEVGs) for tissue regeneration either in vitro or in vivo. However, very limited success has been achieved due to mechanical failure, thrombogenicity or intimal hyperplasia, and improvements of the SD-TEVG design are thus required. Here, in vivo studies investigating novel and relative long (10 times of the inner diameter) SD-TEVGs in large animal models and humans are identified and discussed, with emphasis on graft outcome based on model- and graft-related conditions. Only a few types of synthetic polymer-based SD-TEVGs have been evaluated in large-animal models and reflect limited success. However, some polymers, such as polycaprolactone (PCL), show favorable biocompatibility and potential to be further modified and improved in the form of hybrid grafts. Natural polymer- and cell-secreted extracellular matrix (ECM)-based SD-TEVGs tested in large animals still fail due to a weak strength or thrombogenicity. Similarly, native ECM-based SD-TEVGs and in-vitro-developed hybrid SD-TEVGs that contain xenogeneic molecules or matrix seem related to a harmful graft outcome. In contrast, allogeneic native ECM-based SD-TEVGs, in-vitro-developed hybrid SD-TEVGs with allogeneic banked human cells or isolated autologous stem cells, and in-body tissue architecture (IBTA)-based SD-TEVGs seem to be promising for the future, since they are suitable in dimension, mechanical strength, biocompatibility, and availability.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2874
Author(s):  
Hengfeng Yuan ◽  
Wen Jiang ◽  
Yuanxin Chen ◽  
Betty Kim

Ischemic injuries and local hypoxia can result in osteocytes dysfunction and play a key role in the pathogenesis of avascular osteonecrosis. Conventional imaging techniques including magnetic resonance imaging (MRI) and computed tomography (CT) can reveal structural and functional changes within bony anatomy; however, characterization of osteocyte behavioral dynamics in the setting of osteonecrosis at the single cell resolution is limited. Here, we demonstrate an optical approach to study real-time osteocyte functions in vivo. Using nicotinamide adenine dinucleotide (NADH) as a biomarker for metabolic dynamics in osteocytes, we showed that NADH level within osteocytes transiently increase significantly after local ischemia through non-invasive photo-induced thrombosis of afferent arterioles followed by a steady decline. Our study presents a non-invasive optical approach to study osteocyte behavior through the modulation of local environmental conditions. Thus it provides a powerful toolkit to study cellular processes involved in bone pathologies in vivo.


2011 ◽  
Vol 142 (6) ◽  
pp. 1585-1587 ◽  
Author(s):  
Mathieu Granier ◽  
Morten O. Jensen ◽  
Jesper L. Honge ◽  
Alain Bel ◽  
Philippe Menasché ◽  
...  

2018 ◽  
Author(s):  
Lawrance Chandra ◽  
Dana C Borcherding ◽  
Dawn Kingsbury ◽  
Todd Atherly ◽  
Yoko M Ambrosini ◽  
...  

AbstractBackgroundLarge animal models, such as the dog, are increasingly being used over rodent models for studying naturally occurring diseases including gastrointestinal (GI) disorders. Dogs share similar environmental, genomic, anatomical, and intestinal physiologic features with humans. To bridge the gap between currently used animal models (e.g. mouse) and humans, and expand the translational potential of the dog model, we developed a three dimensional (3D) canine GI organoid (enteroid and colonoid) system. Organoids have recently gained interest in translational research as this model system better recapitulates the physiological and molecular features of the tissue environment in comparison with two-dimensional cultures.ResultsOrganoids were propagated from isolation of adult intestinal stem cells (ISC) from whole jejunal tissue as well as endoscopically obtained duodenal, ileal and colonic biopsy samples of healthy dogs and GI cases, including inflammatory bowel disease (IBD) and intestinal carcinomas. Intestinal organoids were comprehensively characterized using histology, immunohistochemistry, RNA in situ hybridization and transmission electron microscopy, and organoids mimicked the in vivo tissue environment. Physiological relevance of the enteroid system was defined using functional assays such as Optical Metabolic Imaging (OMI), the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) function assay, and Exosome-Like Vesicles (EV) uptake assay, as a basis for wider applications of this technology in basic, preclinical and translational GI research.ConclusionsIn summary, our findings establish the canine GI organoid systems as a novel model to study naturally occurring intestinal diseases in dogs and humans. Furthermore, canine organoid systems will help to elucidate host-pathogen interactions contributing to GI disease pathogenesis.


2019 ◽  
Vol 174 (1) ◽  
pp. 124-132 ◽  
Author(s):  
Kevin G McGarry ◽  
Kevin E Schill ◽  
Tyson P Winters ◽  
Erin E Lemmon ◽  
Carol L Sabourin ◽  
...  

Abstract Organophosphorus (OP) compounds, which include insecticides and chemical warfare nerve agents (CWNAs) such as sarin (GB) and VX, continue to be a global threat to both civilian and military populations. It is widely accepted that cholinesterase inhibition is the primary mechanism for acute OP toxicity. Disruption of cholinergic function through the inhibition of acetylcholinesterase (AChE) leads to the accumulation of the neurotransmitter acetylcholine. Excess acetylcholine at the synapse results in an overstimulation of cholinergic neurons which manifests in the common signs and symptoms of OP intoxication (miosis, increased secretions, seizures, convulsions, and respiratory failure). The primary therapeutic strategy employed in the United States to treat OP intoxication includes reactivation of inhibited AChE with the oxime pralidoxime (2-PAM) along with the muscarinic acetylcholine receptor antagonist atropine and the benzodiazepine, diazepam. CWNAs are also known to inhibit butyrylcholinesterase (BChE) without any apparent toxic effects. Therefore, BChE may be viewed as a “bioscavenger” that stoichiometrically binds CWNAs and removes them from circulation. The degree of inhibition of AChE and BChE and the effectiveness of 2-PAM are known to vary among species. Animal models are imperative for evaluating the efficacy of CWNA medical countermeasures, and a thorough characterization of available animal models is important for translating results to humans. Thus, the objective of this study was to compare the circulating levels of each of the cholinesterases as well as multiple kinetic properties (inhibition, reactivation, and aging rates) of both AChE and BChE derived from humans to AChE and BChE derived from commonly used large animal models.


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