Uranium (U) speciation was investigated in anoxically preserved porewater samples of a natural mountain wetland in Gola di Lago, Ticino, Switzerland. U porewater concentrations ranged from less than 1 μg/L to tens of μg/L, challenging the available analytical approaches for U speciation in natural samples. Asymmetrical flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry allowed the characterization of colloid populations and the determination of the size distribution of U species in the porewater.
View Article and Find Full Text PDFBackground: Left ventricular hypertrophy (LVH) is a potent risk factor for sudden death and congestive heart failure.
Methods: We tested the effect of sorafenib, a multikinase inhibitor (10 mg/kg, given orally, starting 2 days prior to banding, till sacrifice on day 14), on the development of LVH following aortic banding in rats.
Results: The latter resulted in significant LVH caused by both an increase in cardiomyocyte volume and interstitial collagen deposition.
Purpose: Hyperkalaemia due to potassium-increasing drug-drug interactions (DDIs) is a clinically important adverse drug event. The purpose of this study was to identify patient- and physician-related risk factors for the development of hyperkalaemia.
Methods: The risk for adult patients hospitalised in the University Hospital Zurich between 1 December 2009 and 31 December 2011 of developing hyperkalaemia was correlated with patient characteristics, number, type and duration of potassium-increasing DDIs and frequency of serum potassium monitoring.
Stud Health Technol Inform
April 2015
Electronic alerts for preventing hyperkalaemia during potassium-increasing drug-drug-interactions (DDIs) are often overridden due to their low specificity. Treatments of 76,467 inpatients were retrospectively analysed to establish more specific alerts. Alerting concepts for identifying DDIs that induced hyperkalaemia (serum potassium ≥5.
View Article and Find Full Text PDFObjectives: This study sought to investigate the combination of transcatheter aortic valve implantation and a novel concept of stem cell-based, tissue-engineered heart valves (TEHV) comprising minimally invasive techniques for both cell harvest and valve delivery.
Background: TAVI represents an emerging technology for the treatment of aortic valve disease. The used bioprostheses are inherently prone to calcific degeneration and recent evidence suggests even accelerated degeneration resulting from structural damage due to the crimping procedures.
Living autologous tissue engineered vascular-grafts (TEVGs) with growth-capacity may overcome the limitations of contemporary artificial-prostheses. However, the multi-step in vitro production of TEVGs requires extensive ex vivo cell-manipulations with unknown effects on functionality and quality of TEVGs due to an accelerated biological age of the cells. Here, the impact of biological cell-age and tissue-remodeling capacity of TEVGs in relation to their clinical long-term functionality are investigated.
View Article and Find Full Text PDFComputer-triggered reminders alerting physicians on every potentially harmful drug-drug-interaction (DDI) induce alert fatigue due to frequent messages of limited clinical relevance. On demand DDI-checks, however, are not commonly used by physicians. Optimal strategies for sustained quality assurance have to consider patients' risk factors and focus on the most significant DDIs only.
View Article and Find Full Text PDFPrenatal heart valve interventions aiming at the early and systematic correction of congenital cardiac malformations represent a promising treatment option in maternal-fetal care. However, definite fetal valve replacements require growing implants adaptive to fetal and postnatal development. The presented study investigates the fetal implantation of prenatally engineered living autologous cell-based heart valves.
View Article and Find Full Text PDFObjectives: We have previously demonstrated the functionality and growth of autologous, living, tissue-engineered vascular grafts (TEVGs) in long-term animal studies. These grafts showed substantial in vivo tissue remodeling and approximation to native arterial wall characteristics. Based on this, in vitro and in vivo matrix metalloproteinase (MMP) activity of TEVGs is investigated as a key marker of matrix remodeling.
View Article and Find Full Text PDFAims: A living heart valve with regeneration capacity based on autologous cells and minimally invasive implantation technology would represent a substantial improvement upon contemporary heart valve prostheses. This study investigates the feasibility of injectable, marrow stromal cell-based, autologous, living tissue engineered heart valves (TEHV) generated and implanted in a one-step intervention in non-human primates.
Methods And Results: Trileaflet heart valves were fabricated from non-woven biodegradable synthetic composite scaffolds and integrated into self-expanding nitinol stents.
Objectives: The aim of this study was to demonstrate the feasibility of combining the novel heart valve replacement technologies of: 1) tissue engineering; and 2) minimally-invasive implantation based on autologous cells and composite self-expandable biodegradable biomaterials.
Background: Minimally-invasive valve replacement procedures are rapidly evolving as alternative treatment option for patients with valvular heart disease. However, currently used valve substitutes are bioprosthetic and as such have limited durability.
Current scientific attempts to generate in vitro tissue-engineered living blood vessels (TEBVs) show substantial limitations, thereby preventing routine clinical use. In the present report, we describe a novel biotechnology concept to create living small diameter TEBV based exclusively on microtissue self-assembly (living cellular re-aggregates). A novel bioreactor was designed to assemble microtissues in a vascular shape and apply pulsatile flow and circumferential mechanical stimulation.
View Article and Find Full Text PDFObjective: Cardioprotective properties of recombinant human Erythropoietin (rhEpo) have been shown in in vivo regional or ex vivo global models of ischemia-reperfusion (I/R) injury. The aim of this study was to characterize the cardioprotective potential of rhEPO in an in vivo experimental model of global I/R approximating the clinical cardiac surgical setting and to gain insights into the myocardial binding sites of rhEpo and the mechanism involved in its cardioprotective effect.
Methods: Hearts of donor Lewis rats were arrested with cold crystalloid cardioplegia and after 45 min of cold global ischemia grafted heterotopically into the abdomen of recipient Lewis rats.
Smooth muscle cell (SMC) migration contributes to vascular remodeling. Nitric oxide (NO) produced via endothelial NO synthase (eNOS) inhibits SMC migration. This study analyzes signal transduction mechanisms of SMC migration targeted by NO.
View Article and Find Full Text PDFObjective: Monitoring of cardiac surgical patients after transfer from the intensive care unit to the normal ward is incomplete. Undetected hypoxia, however, is known to be a risk factor for occurrence of atrial fibrillation. We have utilized Auricall for continuous wireless monitoring of oxygen saturation and heart rate until discharge.
View Article and Find Full Text PDFBackground And Aim Of The Study: Fetal stem cells represent a promising cell source for heart valve tissue engineering. In particular, amniotic fluid-derived cells (AFDC) have been shown to lead to autologous fetal-like heart valve tissues in vitro for pediatric application. In order to expand the versatility of these cells also for adult application, cryopreserved AFDC were investigated as a potential life-long available cell source for heart valve tissue engineering.
View Article and Find Full Text PDFIntroduction: Latest techniques enable positioning of devices into the coronary sinus (CS) for mitral valve (MV) annuloplasty. We evaluate the feasibility of non-invasive assessment to determine CS anatomy and its relation to MV annulus and coronary arteries by multi-slice CT (MSCT) in normal and insufficient MV.
Methods: Fifty patients (33 males, 17 females, age 67+/-11 years) were studied retrospectively by 64-MSCT scans for anatomical criteria regarding CS and its relation to MV annulus and circumflex artery (CX).
Background: A novel concept providing prenatally tissue engineered human autologous heart valves based on routinely obtained fetal amniotic fluid progenitors as single cell source is introduced.
Methods And Results: Fetal human amniotic progenitors were isolated from routinely sampled amniotic fluid and sorted using CD133 magnetic beads. After expansion and differentiation, cell phenotypes of CD133- and CD133+ cells were analyzed by immunohistochemistry and flowcytometry.
Introduction: Surgical repair of the mitral valve is in most cases limited to the posterior leaflet of the mitral valve and to the annulus fibrosus. The term annulus fibrosus is still used in anatomical and clinical terminology and is described as a cord like structure providing the attachment of the mitral vale. However, to date no evidence exists of a ring-or cord-like structure at this area.
View Article and Find Full Text PDFSleep apnoea syndrome is frequent in patients with heart failure and associated with a worse prognosis. We evaluated a new device (Auricall) for non-invasive, continuous recording of oxygen saturation (SpO(2)) and heart rate (HR) in patients with heart failure. We studied 20 patients (mean age 48.
View Article and Find Full Text PDFInteract Cardiovasc Thorac Surg
December 2002
With the DaVinci Robot only recently in clinical use, limitations of video-assisted thoracoscopy could disappear due to Endo-Wrist features, tremor cancellation and three-dimensional view. This report describes the total endoscopic pericardiectomy successfully achieved with robotic assistance in a 50-year-old man suffering from effusive pericarditis.
View Article and Find Full Text PDFThis study demonstrates the engineering of biologically active heart valve leaflets using prenatally available human umbilical cord-derived progenitor cells as the only cell source. Wharton's Jelly-derived cells and umbilical cord blood-derived endothelial progenitor cells were subsequently seeded on biodegradable scaffolds and cultured in a biomimetic system under biochemical or mechanical stimulation or both. Depending on the stimulation, leaflets showed mature layered tissue formation with functional endothelia and extracellular matrix production comparable with that of native tissues.
View Article and Find Full Text PDFWire fixation after median sternotomy is a safe procedure, but it is still associated with potential wound infection including bony dehiscence. In case of infection and dehiscence the sternum is re-fixated with steel wires. If this is insufficient, then flap reconstruction would be another option.
View Article and Find Full Text PDFConf Proc IEEE Eng Med Biol Soc
September 2007
A novel tactile device based on a monolithically integrated sensor chip is presented for external blood pressure measurement. It uses a tonometric principle, thus allowing for continuous monitoring of the blood pressure without the need for an invasive catheter. On the chip, the deflection of membranes in an array is sensed capacitively and read out using a SigmaDelta-modulator.
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