39 research outputs found
RVOT-Rekonstruktion mit dem LabcorÂź stentless valved pulmonary conduit: mittelfristige Ergebnisse
Bei angeborenen Herzfehlern oder Operationen mit Beteiligung der Pulmonalklappe bzw. des rechtsventrikulĂ€ren Ausflusstraktes bedĂŒrfen die Patienten eines geeigneten Ersatzes der Pulmonalklappe. Bis jetzt ist der Einsatz eines Homografts das Mittel der Wahl, jedoch mit dem Problem der begrenzten VerfĂŒgbarkeit. Daher haben sich kĂŒnstliche Herzklappen aus Fremdgewebe von Rind oder Schwein etabliert. Diese erreichen in ihrer Funktion und Haltbarkeit zwar noch nicht die QualitĂ€t der Homografts, unterscheiden sich jedoch in Bezug auf Patienten- und Conduit-abhĂ€ngige Einflussfaktoren. In der vorliegenden Studie untersuchten wir das Xenograft-Modell Labcor, bestehend aus einem Rinderperikardrohr mit einer porcinen Aortenklappe, hinsichtlich seiner Funktion und Haltbarkeit in situ. Dazu werteten wir retrospektiv die Daten von 53 Patienten aus, denen dieses Modell im UKSH Kiel zwischen Februar 2009 und Juli 2016 implantiert wurde. Die hĂ€ufigste Diagnose war die Fallot-Tetralogie (35,8%). Das mediane Alter bei Labcor-Implantation betrug 10 Jahre, der mediane Durchmesser der implantierten Conduits 21 mm. Das Follow-Up dauerte im Median 4,6 Jahre. WĂ€hrend der Nachbeoachtung entwickelten 14 Patienten (27,5%) ein Conduitversagen hauptsĂ€chlich mit der Ursache einer Conduitstenose. Nach fĂŒnf Jahren betrug die Freiheit von Herzkatheterintervention 77,5% und die Freiheit von Conduitwechsel 80,5%. Die mediane Haltbarkeit des Conduits betrug 7,4 Jahre. Die LetalitĂ€t betrug 2%. Im Zusammenhang mit frĂŒhem Conduitversagen standen junges Patientenalter bei Implantation sowie ein kleiner Conduitdurchmesser. Der Einsatz des Labcor-Conduits fĂŒhrt mittelfristig zu akzeptablen Ergebnissen, womit diese Daten vergleichbar mit der aktuellen Datenlage zu anderen Conduits sind. FĂŒr die Beurteilung auf langfristige Sicht sind weitere Studien erforderlich
H-ferritin ferroxidase induces cytoprotective pathways and inhibits microvascular stasis in transgenic sickle mice
Hemolysis, oxidative stress, inflammation, vaso-occlusion and organ infarction are hallmarks of sickle cell disease (SCD). We have previously shown that increases in heme oxygenase-1 (HO-1) activity detoxify heme and inhibit vaso-occlusion in transgenic mouse models of SCD. HO-1 releases Fe2+ from heme, and the ferritin heavy chain (FHC) ferroxidase oxidizes iron to catalytically-inactive Fe3+ inside ferritin. FHC overexpression has been shown to be cytoprotective. In this study, we hypothesized that overexpression of FHC and its ferroxidase activity will inhibit inflammation and microvascular stasis in transgenic sickle mice in response to stroma-free hemoglobin. We utilized a Sleeping Beauty transposase plasmid to deliver a human wild-type-ferritin heavy chain (wt-hFHC) transposable element by hydrodynamic tail vein injections to NY1DD SCD mice. Control mice were infused with the same volume of lactated Ringer's solution (LRS) or a triple missense human FHC (ms-hFHC) plasmid with no ferroxidase activity. Eight weeks later, LRS-injected mice had ~40% microvascular stasis (% non-flowing venules) when infused with stroma-free hemoglobin at 1 h, while mice overexpressing wt-hFHC had only 5% stasis (p< 0.05), and ms-hFHC mice had 33% stasis suggesting vascular protection by ferroxidase active wt-hFHC. The wt-hFHC SCD mice had marked increases in splenic hFHC mRNA and hepatic hFHC protein, light chain ferritin, 5-aminolevulinic acid synthase (5-ALA-synthase), heme content, ferroportin, nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear hFHC, and microsomal HO-1 activity and protein, and a decrease in activated nuclear phosho-nuclear factor-kappa B (NF-ÎșB) p65. HO-1 activity was not essential for the protection by FHC. We conclude that wt-hFHC ferroxidase activity enhances cytoprotective Nrf2-regulated proteins including HO-1, thereby resulting in decreased NF-ÎșB-activation, inflammation and microvascular stasis in transgenic SCD mice
Human Uterine Wall Tension Trajectories and the Onset of Parturition
Uterine wall tension is thought to be an important determinant of the onset of labor in pregnant women. We characterize human uterine wall tension using ultrasound from the second trimester of pregnancy until parturition and compare preterm, term and twin pregnancies. A total of 320 pregnant women were followed from first antenatal visit to delivery during the period 2000â2004 at the John Hunter Hospital, NSW, Australia. The uterine wall thickness, length, anterior-posterior diameter and transverse diameter were determined by serial ultrasounds. Subjects were divided into three groups: women with singleton pregnancies and spontaneous labor onset, either preterm or term and women with twin pregnancies. Intrauterine pressure results from the literature were combined with our data to form trajectories for uterine wall thickness, volume and tension for each woman using the prolate ellipsoid method and the groups were compared at 20, 25 and 30 weeks gestation. Uterine wall tension followed an exponential curve, with results increasing throughout pregnancy with the site of maximum tension on the anterior wall. For those delivering preterm, uterine wall thickness was increased compared with term. For twin pregnancies intrauterine volume was increased compared to singletons (), but wall thickness was not. There was no evidence for increased tension in those delivering preterm or those with twin gestations. These data are not consistent with a role for high uterine wall tension as a causal factor in preterm spontaneous labor in singleton or twin gestations. It seems likely that hormonal differences in multiple gestations are responsible for increased rates of preterm birth in this group rather than increased tension
Pathways to Injury in Chronic Pancreatitis: Decoding the Role of the High-Risk SPINK1 N34S Haplotype Using Meta-Analysis
Background: The complex interactions between recurrent trypsin-mediated pancreatic injury, alcohol-associated pancreatic injury and SPINK1 polymorphisms in chronic pancreatitis (CP) are undefined. We hypothesize that CP occurs as a result of multiple pathological mechanisms (pathways) that are initiated by different metabolic or environmental factors (etiologies) and may be influenced differentially by downstream genetic risk factors. We tested this hypothesis by evaluating the differences in effect size of the high risk SPINK1 N34S haplotype on CP from multiple etiologies after combining clinical reports of SPINK1 N34S frequency using meta-analysis. Methods and Findings: The Pubmed and the Embase databases were reviewed. We studied 24 reports of SPINK1 N34S in CP (2,421 cases, 4,857 controls) using reported etiological factors as surrogates for pathways and multiple meta-analyses to determine the differential effects of SPINK1 N34S between alcoholic and non-alcoholic etiologies. Using estimates of between-study heterogeneity, we sub-classified our 24 studies into four specific clusters. We found that SPINK1 N34S is strongly associated with CP overall (OR 11.00; 95% CI: 7.59-15.93), but the effect of SPINK1 N34S in alcoholic CP (OR 4.98, 95% CI: 3.16-7.85) was significantly smaller than in idiopathic CP (OR 14.97, 95% C.I. = 9.09-24.67) or tropical CP (OR 19.15, 95% C.I. = 8.83-41.56). Studies analyzing familial CP showed very high heterogeneity suggestive of a complex etiology with an I2 = 80.95%. Conclusion: The small effect of SPINK1 N34S in alcoholic subjects suggests that CP is driven through a different pathway that is largely trypsin-independent. The results also suggest that large effect sizes of SPINK1 N34S in small candidate gene studies in CP may be related to a mixture of multiple etiologic pathways leading to the same clinical endpoint. © 2008 Aoun MD et al
Training future generations to deliver evidence-based conservation and ecosystem management
1. To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence-based decisions and of the value of evidence synthesis. 2. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an effective contribution to conservation practice. 3. To help overcome this problem we have created open access online teaching materials in multiple languages that are stored in Applied Ecology Resources. So far, 117 educators from 23 countries have acknowledged the importance of this and are already teaching or about to teach skills in appraising or using evidence in conservation decision-making. This includes 145 undergraduate, postgraduate or professional development courses. 4. We call for wider teaching of the tools and skills that facilitate evidence-based conservation and also suggest that providing online teaching materials in multiple languages could be beneficial for improving global understanding of other subject areas.Peer reviewe
Temporal and spatial analysis of the 2014-2015 Ebola virus outbreak in West Africa
West Africa is currently witnessing the most extensive Ebola virus (EBOV) outbreak so far recorded. Until now, there have been 27,013 reported cases and 11,134 deaths. The origin of the virus is thought to have been a zoonotic transmission from a bat to a two-year-old boy in December 2013 (ref. 2). From this index case the virus was spread by human-to-human contact throughout Guinea, Sierra Leone and Liberia. However, the origin of the particular virus in each country and time of transmission is not known and currently relies on epidemiological analysis, which may be unreliable owing to the difficulties of obtaining patient information. Here we trace the genetic evolution of EBOV in the current outbreak that has resulted in multiple lineages. Deep sequencing of 179 patient samples processed by the European Mobile Laboratory, the first diagnostics unit to be deployed to the epicentre of the outbreak in Guinea, reveals an epidemiological and evolutionary history of the epidemic from March 2014 to January 2015. Analysis of EBOV genome evolution has also benefited from a similar sequencing effort of patient samples from Sierra Leone. Our results confirm that the EBOV from Guinea moved into Sierra Leone, most likely in April or early May. The viruses of the Guinea/Sierra Leone lineage mixed around June/July 2014. Viral sequences covering August, September and October 2014 indicate that this lineage evolved independently within Guinea. These data can be used in conjunction with epidemiological information to test retrospectively the effectiveness of control measures, and provides an unprecedented window into the evolution of an ongoing viral haemorrhagic fever outbreak.status: publishe
KOJAK encodes a cellulose synthase-like protein required for root hair cell morphogenesis in Arabidopsis
The cell wall is an important determinant of plant cell form. Here we define a class of Arabidopsis root hair mutants with defective cell walls. Plants homozygous for kojak (kjk) mutations initiate root hairs that rupture at their tip soon after initiation. The KJK gene was isolated by positional cloning, and its identity was confirmed by the molecular complementation of the Kjk(â) phenotype and the sequence of three kjk mutant alleles. KOJAK encodes a cellulose synthase-like protein, AtCSLD3. KOJAK/AtCSLD3 is the first member of this subfamily of proteins to be shown to have a function in cell growth. Subcellular localization of the KOJAK/AtCSLD3 protein using a GFP fusion shows that KOJAK/AtCSLD3 is located on the endoplasmic reticulum, indicating that KOJAK/AtCSLD3 is required for the synthesis of a noncellulosic wall polysaccharide. Consistent with the cell specific defect in the roots of kjk mutants, KOJAK/AtCSDL3 is preferentially expressed in hair cells of the epidermis. The Kjk(â) phenotype and the pattern of KOJAK/AtCSLD3 expression suggest that this gene acts early in the process of root hair outgrowth. These results suggest that KOJAK/AtCSLD3 is involved in the biosynthesis of ÎČ-glucan-containing polysaccharides that are required during root hair elongation
Right ventricular outflow tract reconstruction with the LabcorÂź stentless valved pulmonary conduit
OBJECTIVES
The right ventricular outflow tract reconstruction is a common necessity in congenital cardiac surgery. As homograft availability is limited, alternatives need to be evaluated. The LabcorÂź conduit consists of a porcine tricomposite valve assembled inside a bovine pericardium tube. This study presents intermediate-term results for its utilization for right ventricular outflow tract reconstruction.
METHODS
Labcor conduits were implanted in 53 patients (February 2009-July 2016). We analysed perioperative data, freedom from conduit failure and risk factors for conduit dysfunction.
RESULTS
The most common diagnosis was Tetralogy of Fallot (nâ=â20, 37.7%). The median age at surgery was 10.0 [interquartile range (IQR) 4.9-14.3] years. Pulmonary artery plasty (nâ=â37, 69.8%) and augmentation of the right ventricular outflow tract (nâ=â16, 30.2%) were often part of the procedure. The median conduit size was 21 (range 11-25) mm. There was no in-hospital death. The median follow-up after surgery was 4.6 (IQR 3.4-5.6) years. Fourteen patients (27.5%) developed conduit failure with stenosis being the main cause. Freedom from conduit failure was 98.0% at 2 and 80.5% at 5 years. The median longevity of the conduit was 7.4âyears (95% confidence interval 5.1-9.8âyears). Younger age and smaller conduit size were related to conduit failure.
CONCLUSIONS
Utilization of the Labcor conduit revealed acceptable intermediate-term results. The conduit appeared to be functioning sufficiently well within the first 5âyears in the majority of patients. The higher rate of failure concerning smaller conduits might be associated with somatic outgrowth; however, conduit degeneration as common and long-term outcome still needs to be evaluated
Hepatic Overexpression of Hemopexin Inhibits Inflammation and Vascular Stasis in Murine Models of Sickle Cell Disease
Abstract Sickle cell disease (SCD) patients have low serum hemopexin (Hpx) levels due to chronic hemolysis. We hypothesized that in SCD mice, hepatic overexpression of hemopexin would scavenge the proximal mediator of vascular activation, heme, and inhibit inflammation and microvascular stasis. To examine the protective role of Hpx in SCD, we transplanted bone marrow from NY1DD SCD mice into Hpxâ/â or Hpx+/+ C57BL/6 mice. Dorsal skin fold chambers were implanted 13 wks post-transplant, and microvascular stasis (% nonflowing venules) was evaluated in response to heme infusion. Hpxâ/â sickle mice had significantly greater microvascular stasis in response to heme infusion than Hpx+/+ sickle mice (p < 0.05), demonstrating the protective effect of Hpx in SCD. We utilized Sleeping Beauty (SB) transposon-mediated gene transfer to overexpress wild-type rat Hpx (wt-Hpx) in NY1DD and Townes-SS SCD mice. Control SCD mice were treated with lactated Ringerâs solution (LRS) or a luciferase (Luc) plasmid. Plasma and hepatic Hpx were significantly increased compared with LRS and Luc controls. Microvascular stasis in response to heme infusion in NY1DD and Townes-SS mice overexpressing wt-Hpx had significantly less stasis than controls (p < 0.05). Wt-Hpx overexpression markedly increased hepatic nuclear Nrf2 expression, HO-1 activity and protein, and the heme-Hpx binding protein and scavenger receptor CD91/LRP1, and decreased NF-ÎșB activation. Two missense (ms)-Hpx SB constructs that bound neither heme nor the Hpx receptor CD91/LRP1 did not prevent heme-induced stasis. In conclusion, increasing Hpx levels in transgenic sickle mice via gene transfer activates the Nrf2/HO-1 antioxidant axis and ameliorates inflammation and vasoocclusion
Glokalisierung, politische Beteiligung und Protestmobilisierung. Zum Mediationsverfahren Flughafenerweiterung Frankfurt.
Sack D. Glokalisierung, politische Beteiligung und Protestmobilisierung. Zum Mediationsverfahren Flughafenerweiterung Frankfurt. In: Klein A, Koopmans R, Geiling H, eds. Globalisierung - Partizipation - Protest. Opladen: VS-Verlag; 2001: 293-317