107 research outputs found
Delivery of multipotent adult progenitor cells via a functionalized plasma polymerized surface accelerates healing of murine diabetic wounds
Introduction: Stem cell therapies have been investigated as potential treatment modalities for chronic wounds however there has been limited success to date. Multipotent Adult Progenitor Cells (MAPCs©) have been identified as having potential as an allogenic stem cell product due to their high population doubling number and their characteristic dampening of T-cell proliferation. This helps to prevent autoimmunity and graft/cell rejection.Methods: We have developed a dressing, consisting of medical grade silicone coated with a heptylamine plasma polymer, which supports the growth and transfer of MAPCs to skin. To determine if the dressing can deliver functional stem cells into diabetic wounds, they were loaded with MAPCs and then placed over excisional wounds in both normal and diabetic mice.Results and discussion: Accelerated healing was observed in both the normal and diabetic wounds with wound gape being significantly smaller at day 3 when compared to controls. Wound analysis showed that treatment with the MAPC dressings dampened the inflammatory response with reduced numbers of neutrophils and macrophages observed. Additionally, an increase in pro-angiogenic VEGF and CD31 positive endothelial cells was observed indicating improved new blood vessel formation. The MAPC dressings had no effect on fibrosis with collagen I and III being equally affected in both control and treated wounds. Overall, the functionalized MAPC dressings improve healing responses particularly in diabetic mice with impaired healing responses and therefore, show potential for development as an advanced therapeutic approach for the treatment of chronic diabetic wounds
Colonic migrating motor complexes are inhibited in acute tri-nitro benzene sulphonic acid colitis
Published: June 22, 2018Background
Inflammatory Bowel Disease (IBD) is characterized by overt inflammation of the intestine and is typically accompanied by symptoms of bloody diarrhea, abdominal pain and cramping. The Colonic Migrating Motor Complex (CMMC) directs the movement of colonic luminal contents over long distances. The tri-nitrobenzene sulphonic acid (TNBS) model of colitis causes inflammatory damage to enteric nerves, however it remains to be determined whether these changes translate to functional outcomes in CMMC activity. We aimed to visualize innate immune cell infiltration into the colon using two-photon laser scanning intra-vital microscopy, and to determine whether CMMC activity is altered in the tri-nitro benzene sulphonic (TNBS) model of colitis.
Methods
Epithelial barrier permeability was compared between TNBS treated and healthy control mice in-vitro and in-vivo. Innate immune activation was determined by ELISA, flow cytometry and by 2-photon intravital microscopy. The effects of TNBS treatment and IL-1β on CMMC function were determined using a specialized organ bath.
Results
TNBS colitis increased epithelial barrier permeability in-vitro and in-vivo. Colonic IL-1β concentrations, colonic and systemic CD11b+ cell infiltration, and the number of migrating CD11b+ cells on colonic blood vessels were all increased in TNBS treated mice relative to controls. CMMC frequency and amplitude were inhibited in the distal and mid colon of TNBS treated mice. CMMC activity was not altered by superfusion with IL-1β.
Conclusions
TNBS colitis damages the epithelial barrier and increases innate immune cell activation in the colon and systemically. Innate cell migration into the colon is readily identifiable by two-photon intra-vital microscopy. CMMC are inhibited by inflammation, but this is not due to direct effects of IL-1β.Ben R. Hofma, Hannah R. Wardill, Chris Mavrangelos, Melissa A. Campaniello, David Dimasi, Joanne M. Bowen, Scott D. Smid, Claudine S. Bonder, Elizabeth A. Beckett, Patrick A. Hughe
Antithrombotic therapy in patients undergoing TAVI: an overview of Dutch hospitals
To assess current antithrombotic treatment strategies in the Netherlands in patients undergoing transcatheter aortic valve implantation (TAVI). For every Dutch hospital performing TAVI (n = 14) an interventional cardiologist experienced in performing TAVI was interviewed concerning heparin, aspirin, thienopyridine and oral anticoagulation treatment in patients undergoing TAVI. The response rate was 100 %. In every centre, a protocol for antithrombotic treatment after TAVI was available. Aspirin was prescribed in all centres, concomitant clopidogrel was prescribed 13 of the 14 centres. Duration of concomitant clopidogrel was 3 months in over two-thirds of cases. In 2 centres, duration of concomitant clopidogrel was based upon type of prosthesis: 6 months versus 3 months for supra-annular and intra-annular prostheses, respectively. Leaning on a small basis of evidence and recommendations, the antithrombotic policy for patients undergoing TAVI is highly variable in the Netherlands. As a standardised regimen might further reduce haemorrhagic complications, large randomised clinical trials may help to establish the most appropriate approac
The influence of implantation techniques on lesion oriented-outcomes in Absorb BVS and Xience EES lesions treated in routine clinical practice at complete three year follow-up: AIDA trial QCA substudy
It has been hypothesized that dedicated optimized Absorb BVS implantation techniques might mitigate the risk of adverse events such as target vessel
Cilostazol Activates Function of Bone Marrow-Derived Endothelial Progenitor Cell for Re-endothelialization in a Carotid Balloon Injury Model
BACKGROUND: Cilostazol(CLZ) has been used as a vasodilating anti-platelet drug clinically and demonstrated to inhibit proliferation of smooth muscle cells and effect on endothelial cells. However, the effect of CLZ on re-endothelialization including bone marrow (BM)-derived endothelial progenitor cell (EPC) contribution is unclear. We have investigated the hypothesis that CLZ might accelerate re-endothelialization with EPCs. METHODOLOGY/PRINCIPAL FINDINGS: Balloon carotid denudation was performed in male Sprague-Dawley rats. CLZ group was given CLZ mixed feed from 2 weeks before carotid injury. Control group was fed normal diet. CLZ accelerated re-endothelialization at 2 weeks after surgery and resulted in a significant reduction of neointima formation 4 weeks after surgery compared with that in control group. CLZ also increased the number of circulating EPCs throughout the time course. We examined the contribution of BM-derived EPCs to re-endothelialization by BM transplantation from Tie2/lacZ mice to nude rats. The number of Tie2-regulated X-gal positive cells on injured arterial luminal surface was increased at 2 weeks after surgery in CLZ group compared with that in control group. In vitro, CLZ enhanced proliferation, adhesion and migration activity, and differentiation with mRNA upregulation of adhesion molecule integrin αvβ3, chemokine receptor CXCR4 and growth factor VEGF assessed by real-time RT-PCR in rat BM-derived cultured EPCs. In addition, CLZ markedly increased the expression of SDF-1α that is a ligand of CXCR4 receptor in EPCs, in the media following vascular injury. CONCLUSIONS/SIGNIFICANCE: CLZ promotes EPC mobilization from BM and EPC recruitment to sites of arterial injury, and thereby inhibited neointima formation with acceleration of re-endothelialization with EPCs as well as pre-existing endothelial cells in a rat carotid balloon injury model. CLZ could be not only an anti-platelet agent but also a promising tool for endothelial regeneration, which is a key event for preventing atherosclerosis or restenosis after vascular intervention
Increasing arterial wall injury after long-term implantation of two types of stent in a porcine coronary model
Geen voordeel voor patiënten met een acuut myocardinfarct die vanuit een algemeen ziekenhuis verwezen werden naar een interventiecentrum voor dotterbehandeling; vergelijking van mortaliteitscijfers van 2000 en 2003 in het Meander Medisch Centrum, Amersfoort
Differentiable strong lensing: Uniting gravity and neural nets through differentiable probabilistic programming
Since upcoming telescopes will observe thousands of strong lensing systems, creating fully automated analysis pipelines for these images becomes increasingly important. In this work, we make a step towards that direction by developing the first end-to-end differentiable strong lensing pipeline. Our approach leverages and combines three important computer science developments: (i) convolutional neural networks (CNNs), (ii) efficient gradient-based sampling techniques, and (iii) deep probabilistic programming languages. The latter automatize parameter inference and enable the combination of generative deep neural networks and physics components in a single model. In the current work, we demonstrate that it is possible to combine a CNN trained on galaxy images as a source model with a fully differentiable and exact implementation of gravitational lensing physics in a single probabilistic model. This does away with hyperparameter tuning for the source model, enables the simultaneous optimization of nearly 100 source and lens parameters with gradient-based methods, and allows the use of efficient gradient-based posterior sampling techniques. These features make this automated inference pipeline potentially suitable for processing a large amount of data. By analysing mock lensing systems with different signal-to-noise ratios, we show that lensing parameters are reconstructed with per cent-level accuracy. More generally, we consider this work as one of the first steps in establishing differentiable probabilistic programming techniques in the particle astrophysics community, which have the potential to significantly accelerate and improve many complex data analysis tasks
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