96 research outputs found

    The effects of interventional mitral valve repair using the MitraClip System on the results of pulmonary function testing, pulmonary pressure and diffusing capacity of the lung

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    Background: The study analyzes changes in lung function, pulmonary pressure and diffusing capacity of the lung in patients with mitral valve regurgitation (MR) treated by MitraClip implantation. Methods: A total of 43 patients (19 women and 24 men with an average age of 78.0 +/- 6.6 years) who were able to perform pulmonary function testing including diffusing capacity of the lung for carbon monoxide (DLCO), vital capacity (VC), total lung capacity (TLC), residual volume (RV) and forced expiratory volume in 1 s (FEV1) before and 6 weeks after MitraClip implantation participated in this study. Furthermore, clinical and echocardiographic parameters including systolic pulmonary artery pressure (sPAP), left ventricular ejection fraction (LVEF) and left atrial diameter (LAD) measurements were recorded in all patients. Results: The procedure was performed successfully in all 43 patients leading to a reduction of MR in 97.7% of cases. One patient died on day 4 after the intervention most likely due to pulmonary artery embolism. Six weeks after the implantation 79.1% of patients showed a MR of at most mild to moderate. Furthermore, we could demonstrate a significant reduction of systolic pulmonary artery pressure during follow-up (from 48.8 +/- 11.4 mmHg to 42.9 +/- 9.0 mmHg (t(41) = - 2.6, p = 0.01). However, no changes in LVEF were detected. Comparing pre and post implant lung function tests, no significant alterations were seen for VC, TLC, DLCO and FEV1. Though, in a subgroup of patients with moderate to severe preexisting deterioration of DLCO at the baseline (max. 50%) the MitraClip procedure resulted in a significant improvement in DLCO (37.8% +/- 9.0 to 41.6% +/- 10.0, p < 0.001). Conclusions: Treatment of MR with the MitraClip system successfully reduces MR severity in the vast majority of patients. Consecutively, a reduction in pulmonary pressure could be observed, however no changes in LVEF were obvious. Lung function tests remained unaltered during follow-up. However, in a subgroup of patients with severe preexisting deterioration of DLCO the MitraClip procedure resulted in a significant improvement in DLCO

    Plasmonic Hepatitis B Biosensor for the Analysis of Clinical Saliva

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    A biosensor for the detection of hepatitis B antibodies in clinical saliva was developed. Compared to conventional analysis of blood serum, it offers the advantage of noninvasive collection of samples. Detection of biomarkers in saliva imposes two major challenges associated with the low analyte concentration and increased surface fouling. The detection of minute amounts of hepatitis B antibodies was performed by plasmonically amplified fluorescence sandwich immunoassay. To have access to specific detection, we prevented the nonspecific adsorption of biomolecules present in saliva by brushes of poly[(N-(2-hydroxypropyl) methacrylamide)-co-(carboxybetaine methacrylamide)] grafted from the gold sensor surface and post modified with hepatitis B surface antigen. Obtained results were validated against the response measured with ELISA at a certified laboratory using serum from the same patients. © 201

    The Effect of Reagents Mimicking Oxidative Stress on Fibrinogen Function

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    Fibrinogen is one of the plasma proteins most susceptible to oxidative modification. It has been suggested that modification of fibrinogen may cause thrombotic/bleeding complications associated with many pathophysiological states of organism. We exposed fibrinogen molecules to three different modification reagents—malondialdehyde, sodium hypochlorite, and peroxynitrite—that are presented to various degrees in different stages of oxidative stress. We studied the changes in fibrin network formation and platelet interactions with modified fibrinogens under flow conditions. The fastest modification of fibrinogen was caused by hypochlorite. Fibers from fibrinogen modified with either reagent were thinner in comparison with control fibers. We found that platelet dynamic adhesion was significantly lower on fibrinogen modified with malondialdehyde and significantly higher on fibrinogen modified either with hypochlorite or peroxynitrite reflecting different prothrombotic/antithrombotic properties of oxidatively modified fibrinogens. It seems that, in the complex reactions ongoing in living organisms at conditions of oxidation stress, hypochlorite modifies proteins (e.g., fibrinogen) faster and more preferentially than malondialdehyde. It suggests that the prothrombotic effects of prior fibrinogen modifications may outweigh the antithrombotic effect of malondialdehyde-modified fibrinogen in real living systems

    Vascular Response on a Novel Fibrin-Based Coated Flow Diverter

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    Purpose Due to thromboembolic complications and in-stent-stenosis after flow diverter (FD) treatment, the long-term use of dual antiplatelet treatment (DAPT) is mandatory. The tested nano-coating has been shown to reduce material thrombogenicity and promote endothelial cell proliferation in vitro. We compared the biocompatibility of coated (Derivo Heal) and non-coated (Derivo bare) FDs with DAPT in an animal model. Methods Derivo® bare (n = 10) and Derivo® Heal (n = 10) FD were implanted in the common carotid arteries (CCAs) of New Zealand white rabbits. One additional FD, alternately a Derivo bare (n = 5) or Derivo Heal (n = 5), was implanted in the abdominal aorta (AA) for assessment of the patency of branch arteries. Histopathological examinations were performed after 28 days. Angiography was performed before and after FD implantation and at follow-up. Results Statistical analysis of the included specimens showed complete endothelialization of all FDs with no significant differences in neointima thickness between Derivo® bare and Derivo® Heal (CCA: p = 0.91; AA: p = 0.59). A significantly reduced number of macrophages in the vessel wall of the Derivo Heal was observed for the CCA (p = 0.02), and significantly reduced fibrin and platelet deposition on the surface of the Derivo Heal was observed for the AA. All branch arteries of the stented aorta remained patent. Conclusion In this animal model, the novel fibrin-based coated FD showed a similar blood and tissue compatibility as the non-coated FD

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Comparison of the hemocompatibility of neurovascular flow diverters with anti-thrombogenic coatings

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    Despite the continual progress in technology, thromboembolic complications still occur following endovascular treatment of cerebral aneurysms and remain the primary contributor to morbidity and mortality. Thus, coating the surfaces of blood-contacting flow diverters may reduce thrombus-related complications in clinical use. In this study, the hemocompatibility of different commercially available flow diverters Pipeline Flex Embolization Device with Shield Technology (Medtronic), the p64 MW HPC (Phenox), and the DERIVO 2heal (Acandis) was investigated using an in vitro blood circulation model. The DERIVO 2 flow diverter was included in this study as an uncoated device. The markers of coagulation (thrombin-antithrombin complex (TAT)), thrombocytes (β-thromboglobulin (β-TG)), inflammation (PMN elastase), and complement system (SC5b-9, C3a, and C5a) activation were detected by enzyme-linked immunosorbent assay (ELISA). In addition to blood cell counts and hemolysis, thrombogenicity was determined using scanning electron microscopy. Flow diverters with anti-thrombogenic coatings resulted in significantly lower activation of coagulation (TAT) and platelets (β-TG) and lower adhesion of platelets compared with the uncoated DERIVO 2 flow diverter. There were no significant differences between the coated flow diverters in terms of TAT and β-TG levels, as well as platelet adhesion. However, significantly lower activation of the complement system (SC5b-9 and C5a) was observed for the DERIVO 2heal flow diverter in comparison with the Pipeline Flex Shield and the p64 MW HPC flow diverters emphasizing the improved hemocompatibility of the fibrin/heparin-coated DERIVO 2heal flow diverter

    Investigation of the velocity distribution in the flow of a journal bearing model

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    In many previous studies the main focus was put on the pressure distribution in the lubricating gap. Due to the limited space in the gap an investigation of the velocity distribution is very difficult or rather impossible. Based on the geometrical shapes of a real journal bearing, a bearing model test rig with an increased relative gap width has been developed. Thus, it is possible to detect the distribution of the flow speed within the gap by using a Laser Doppler Velocimeter (LDV). The comparability of the flow to the flow in a real journal bearing is ensured by observing the Reynolds similarity. Due to a targeted eccentricity in the system and the circumferential groove over 180°, there is in connection with the outlet hole in the rotating shaft a permanent change in the outflow conditions. The consequence is a periodically varying system pressure with effects to the pressure and volumetric flow rate at the inlet and outlet. The velocity measurements with a triggered LDV are done by considering these transient boundary conditions at the system boundaries. In this paper the experimental setup, the expiration of the investigations and some exemplary results are presented. Attendant to the experiment, numerical simulations are carried out and the results are compared with the experimental data

    Causes of Transition from Democracy to Totalitarism

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    Additional file 6: Table S2. Summary of proteins annotated as substrate-binding proteins (SBP) from ATP-binding cassette (ABC) transporters detected in the proteomes of Paenibacillus O199. Annotation was performed with RAST
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