23 research outputs found
The marvel of percutaneous cardiovascular devices in the elderly
Thanks to minimally invasive procedures, frail and elderly patients can also benefit from innovative technologies. More than 14 million implanted pacemakers deliver impulses to the heart muscle to regulate the heart rate (treating bradycardias and blocks). The first human implantation of defibrillators was performed in early 2000. The defibrillator detects cardiac arrhythmias and corrects them by delivering electric shocks. The ongoing development of minimally invasive technologies has also broadened the scope of treatment for elderly patients with vascular stenosis and aneurysmal disease as well as other complex vascular pathologies. The nonsurgical cardiac valve replacement represents one of the most recent and exciting developments, demonstrating the feasibility of replacing a heart valve by way of placement through an intra-arterial or trans-ventricular sheath. Percutaneous devices are particularly well suited for the elderly as the surgical risks of minimally invasive surgery are considerably less as compared to open surgery, leading to a shorter hospital stay, a faster recovery, and improved quality of life
A Floating Thrombus Anchored at the Proximal Anastomosis of a Woven Thoracic Graft Mimicking a Genuine Aortic Dissection
An aortoesophageal fistula following surgery for a ruptured 6.6-cm thoracic aneurysm in a 69-yearold female was repaired using a 34-mm woven prosthetic graft. A follow-up computed tomography (CT) scan at 10 days postoperatively revealed a dissection-like picture in the region of the graft, which was treated conservatively. The patient eventually died from sepsis and multiorgan failure. At autopsy, the graft was retrieved in situ and studied by detailed gross, microscopy, and scanning electron microscopy (SEM) examination. Gross observation confirmed that the dissection resulted from the rolling of the internal capsule downstream. A massive thrombus anchored at the proximal anastomosis and held by a narrow head was also noted. The thrombus demonstrated reorganization in the area of the anastomosis, with a false lumen in its distal half. The reminder of the thrombus consisted of layered fibrin. After gross examination, the fabric graft was found to be flawless. Additional detailed studies were also done using microscopy, SEM, and gross examination
Effect of Electrical Stimulation on Diabetic Human Skin Fibroblast Growth and the Secretion of Cytokines and Growth Factors Involved in Wound Healing
Diabetic foot ulcers are indicative of an impaired wound healing process. This delay may be resolved through electrical stimulation (ES). The goal of the present study was to evaluate the effect of ES on diabetic fibroblast adhesion and growth, and the secretion of cytokines and growth factors. Diabetic human skin fibroblasts (DHSF) were exposed to various intensities of direct current ES (100, 80, 40 and 20 mV/mm). The effect of ES on fibroblast adhesion and growth was evaluated using Hoechst staining, MTT and trypan blue exclusion assays. The secretion of cytokine and growth factor was assessed by cytokine array and ELISA assay. The long-term effects of ES on DHSF shape and growth were determined by optical microscopy and cell count. We demonstrated that ES at 20 and 40 mV/mm promoted cell adhesion, viability and growth. ES also decreased the secretion of pro-inflammatory cytokines IL-6 and IL-8 yet promoted growth factor FGF7 secretion during 48 h post-ES. Finally, the beneficial effect of ES on fibroblast growth was maintained up to 5 days post-ES. Overall results suggest the possible use of low-intensity direct current ES to promote wound healing in diabetic patients
Factors Influencing the Prescription of Cardiovascular Preventive Therapies in Patients with Peripheral Arterial Disease.
BACKGROUND:Guidelines recommend that patients with peripheral arterial disease should be medically treated to reduce the occurrence of serious cardiovascular events. Despite these recommendations, studies conducted in the early 2000s reported that medical therapies for secondary cardiovascular prevention are not given systematically to patients with peripheral arterial disease (PAD). We identified factors associated with the prescription of preventive therapies in patients with symptomatic PAD. METHODS AND FINDINGS:Consecutive patients with symptomatic peripheral arterial disease (n = 362) treated between 2008 and 2010 in one tertiary care center (CHU de Quebec, Canada) were considered. Data were collected from the medical charts. The main outcome was the combined prescription of three therapies: 1) statins, 2) antiplatelets, 3) angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers. The mean age was 70 years and 43% had a pre-existing coronary artery disease. Antiplatelet therapy was the most prescribed drug (83%). A total of 52% of the patients received the three combined therapies. Less than 10% of patients had a known contraindication to one class of medication. Having at least three cardiovascular risk factors (Odds Ratio (OR) = 4.51; 95% CI: 2.76-7.37) was the factor most strongly associated with the prescription of the combined therapies. Pre-existing coronary artery disease (OR = 2.28; 95% CI: 1.43-3.65) and history of peripheral vascular surgery (OR = 2.30; 95% CI: 1.37-3.86) were two factors independently associated with the prescription of the combined therapies. However, peripheral arterial disease patients with chronic critical limb ischemia were less likely to receive the combined therapies (OR = 0.53; 95% CI: 0.32-0.87) than those with claudication. The retrospective nature of this study, not allowing for an exhaustive report of the contraindication to medication prescription, is the main limitation. CONCLUSION:About half of the patients with peripheral arterial disease were not optimally managed. Patients with multiple cardiovascular risk factors were more likely to receive the combined therapies. We still need to better understand the barriers and facilitators to the application of the guidelines
Intra-Operative Fenestration of Stent Grafts: A Note of Caution Based upon Preliminary In Vitro Observations
Binding Properties of the N-Acetylglucosamine and High-Mannose N-Glycan PP2-A1 Phloem Lectin in Arabidopsis[W]
Phloem Protein2 (PP2) is a component of the phloem protein bodies found in sieve elements. We describe here the lectin properties of the Arabidopsis (Arabidopsis thaliana) PP2-A1. Using a recombinant protein produced in Escherichia coli, we demonstrated binding to N-acetylglucosamine oligomers. Glycan array screening showed that PP2-A1 also bound to high-mannose N-glycans and 9-acyl-N-acetylneuraminic sialic acid. Fluorescence spectroscopy-based titration experiments revealed that PP2-A1 had two classes of binding site for N,N′,N″-triacetylchitotriose, a low-affinity site and a high-affinity site, promoting the formation of protein dimers. A search for structural similarities revealed that PP2-A1 aligned with the Cbm4 and Cbm22-2 carbohydrate-binding modules, leading to the prediction of a β-strand structure for its conserved domain. We investigated whether PP2-A1 interacted with phloem sap glycoproteins by first characterizing abundant Arabidopsis phloem sap proteins by liquid chromatography-tandem mass spectrometry. Then we demonstrated that PP2-A1 bound to several phloem sap proteins and that this binding was not completely abolished by glycosidase treatment. As many plant lectins have insecticidal activity, we also assessed the effect of PP2-A1 on weight gain and survival in aphids. Unlike other mannose-binding lectins, when added to an artificial diet, recombinant PP2-A1 had no insecticidal properties against Acyrthosiphon pisum and Myzus persicae. However, at mid-range concentrations, the protein affected weight gain in insect nymphs. These results indicate the presence in PP2-A1 of several carbohydrate-binding sites, with potentially different functions in the trafficking of endogenous proteins or in interactions with phloem-feeding insects
Newly developed hybrid suture without lubricant: Noninvasive in vivo assessment of biocompatibility with multiparametric MR imaging
Magnetic resonance imaging (MRI) and magnetic resonance (MR) relaxomctry were used to assess noninvasively the tissue response of a new uncoated hybrid braided suture made from a combination of ultra-high-molecular-weight polyethylene (UHMWPE) and polyester (polyethylene terephthalate) (PET) yarns in comparison to a silicone impregnated braided 100% polyester (PET) control suture (Ticron). Both biomaterials were monitored for a period of 30 days following implantation in both incised and nonincised paravertebral rabbit muscles. In all cases, MR images and relaxometry demonstrated that the hybrid suture elicited either a milder or a similar tissue and cellular response compared to the control suture. These findings were confirmed by conventional histological analysis of the surrounding tissues. They also demonstrated that the hybrid suture promoted faster healing in terms of collagen infiltration between the yarns and individual filaments. This milder inflammatory reaction and improved biocompatibility represent a real advantage in the healing performance of sutures for cardiac and vascular surgery, and support the need for continued research and development of hybrid structures. This study also demonstrated the ability of MRI techniques to noninvasively evaluate the biocompatibility of biomaterials. By extending the capacity of MR diagnostic tools from patients to experimental animals, it is now possible to validate the healing performance of foreign materials with statistical reliability and fewer animals
Factors associated with the prescription of the recommended therapies in multivariate analysis.
<p>Factors associated with the prescription of the recommended therapies in multivariate analysis.</p
Prescription of the recommended therapy.
<p>ACEI, angiotensin-converting-enzyme inhibitor; ARB, angiotensin receptor blocker; CAD, coronary artery disease; PAD, peripheral arterial disease.</p
Patient’s demographics and clinical characteristics (n = 362).
<p>Patient’s demographics and clinical characteristics (n = 362).</p