29 research outputs found

    Geology of eastern Muhlig -Hofmannfjella and Filchnerfjella in Dronning Maud Land, East Antarctica; A preliminary report of a Japan-Norway-Germany joint geological investigation

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    The geological history of Filchnerfjella and surrounding areas (2ã‚œE to 8ã‚œE) in central Dronning Maud Land,East Antarctica,is constructed from metamorphic and igneous petrology,and structural investigations.The geology of Filchner-fjella consists mainly of metamorphic rocks accompanied by intrusive rocks.Two stages of metamorphism can be recognized in this area.The earlier stage metamorphism is defined as a porphyroblast stage (garnet,hornblende,and sillimanite stable), and the later one is recognized as a symplectic stage (orthopyroxene and cordieritestable).Taking metamorphic textures and geothermobarometries into account,the rocks experienced an early high-P/medium-T followed by a low-P and high-T stage. Partial melting took place during the low-P/high-T stage,because probable melt of leucocratic gneiss contains cordierite.The field relationships and petrography of the syenite at Filchnerfjella are similar to those of post-tectonic plutons from central Dronning Maud Land,and most of the post-tectonic intrusive rocks have within-plate geochemical features.The structural history in Filchnerfjella and surrounding areas can be divided into the Pan-African stage and the Meso to Cenozoic stage that relates to the break-up of Gondwana

    Temporal trends of molecular markers associated with artemether- lumefantrine tolerance/resistance in Bagamoyo district, Tanzania

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    Background: Development and spread of Plasmodium falciparum resistance to artemisinin-based combination therapy (ACT) constitutes a major threat to recent global malaria control achievements. Surveillance of molecular markers could act as an early warning system of ACT-resistance before clinical treatment failures are apparent. The aim of this study was to analyse temporal trends of established genotypes associated with artemether-lumefantrine tolerance/resistance before and after its deployment as first-line treatment for uncomplicated malaria in Tanzania 2006. Methods: Single nucleotide polymorphisms in the P. falciparum multidrug resistance gene 1 (pfmdr1) N86Y, Y184F, D1246Y and P. falciparum chloroquine transporter gene (pfcrt) K76T were analysed from dried blood spots collected during six consecutive studies from children with uncomplicated P. falciparum malaria in Fukayosi village, Bagamoyo District, Tanzania, between 2004-2011. Results: There was a statistically significant yearly increase of pfmdr1 N86, 184F, D1246 and pfcrt K76 between 2006-2011 from 14% to 61% (yearly OR = 1.38 [95% CI 1.25-1.52] p \u3c 0.0001), 14% to 35% (OR = 1.17 [95% CI 1.07-1.30] p = 0.001), 54% to 85% (OR = 1.21 [95% CI 1.03-1.42] p = 0.016) and 49% to 85% (OR = 1.33 [95% CI 1.17-1.51] p \u3c 0.0001), respectively. Unlike for the pfmdr1 SNP, a significant increase of pfcrt K76 was observed already between 2004-2006, from 26% to 49% (OR = 1.68 [95% CI 1.17-2.40] p = 0.005). From 2006 to 2011 the pfmdr1 NFD haplotype increased from 10% to 37% (OR = 1.25 [95% CI 1.12-1.39] p \u3c 0.0001), whereas the YYY haplotype decreased from 31% to 6% (OR = 0.73 [95% CI 0.56-0.98] p = 0.018). All 390 successfully analysed samples had one copy of the pfmdr1 gene. Conclusion: The temporal selection of molecular markers associated with artemether-lumefantrine tolerance/resistance may represent an early warning sign of impaired future drug efficacy. This calls for stringent surveillance of artemether-lumefantrine efficacy in Tanzania and emphasizes the importance of molecular surveillance as a complement to standard in vivo trials. © 2013 Malmberg et al.; licensee BioMed Central Ltd

    Early results from a prospective, single-arm European trial on decellularized allografts for aortic valve replacement: the ARISE study and ARISE Registry data

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    OBJECTIVES Decellularized aortic homografts (DAH) may provide an additional aortic valve replacement option for young patients due to their potential to overcome the high early failure rate of conventional allogenic and xenogenic aortic valve prostheses. METHODS A prospective, European Union-funded, single-arm, multicentre, safety study was conducted in 8 centres evaluating non-cryopreserved DAH for aortic valve replacement. RESULTS One hundred and forty-four patients (99 male) were prospectively enrolled between October 2015 and October 2018, mean age 33.6 ± 20.8 years; 45% had undergone previous cardiac operations. Mean implanted DAH diameter 22.6 ± 2.4 mm and mean durations for the operation, cardiopulmonary bypass and cross-clamp were 341 ± 140, 174 ± 80 and 126 ± 43 min, respectively. There were 2 early deaths (1 LCA thrombus on day 3 and 1 ventricular arrhythmia 5 h postop) and 1 late death due to endocarditis 4 months postoperatively, resulting in a total mortality of 2.08%. One pacemaker implantation was necessary and 1 DAH was successfully repaired after 6 weeks for early regurgitation following subcoronary implantation. All other DAH were implanted as a free-standing root. After a mean follow-up of 1.54 ± 0.81 years, the primary efficacy end points peak gradient (mean 11.8 ± 7.5 mmHg) and regurgitation (mean 0.42 ± 0.49, grade 0-3) were excellent. At 2.5 years, freedom from explantation/endocarditis/bleeding/stroke was 98.4 ± 1.1%/99.4 ± 0.6%/99.1 ± 0.9%/99.2 ± 0.8%, respectively, with results almost identical to those in an age-matched Ross operation cohort of 212 patients (mean age 34 years) despite DAH patients having undergone >2× more previous procedures. CONCLUSIONS The initial results of the prospective multicentre ARISE trial show DAH to be safe for aortic valve replacement with excellent haemodynamics in the short follow-up period

    Data_Sheet_1_Dynamic electrophysiological mechanism in patients with long-standing persistent atrial fibrillation.docx

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    BackgroundImproved understanding of the mechanisms that sustain persistent and long-standing persistent atrial fibrillation (LSpAF) is essential for providing better ablation solutions. The findings of traditional catheter-based electrophysiological studies can be impacted by the sedation required for these procedures. This is not required in non-invasive body-surface mapping (ECGI). ECGI allows for multiple mappings in the same patient at different times. This would expose potential electrophysiological changes over time, such as the location and stability of extra-pulmonary vein drivers and activation patterns in sustained AF.Materials and methodsIn this electrophysiological study, 10 open-heart surgery candidates with LSpAF, without previous ablation procedures (6 male, median age 73 years), were mapped on two occasions with a median interval of 11 days (IQR: 8–19) between mappings. Bi-atrial epicardial activation sequences were acquired using ECGI (CardioInsight™, Minneapolis, MN, United States).ResultsBi-atrial electrophysiological abnormalities were documented in all 20 mappings. Interestingly, the anatomic location of focal and rotor activities changed between the mappings in all patients [100% showed changes, 95%CI (69.2–100%), p ConclusionThis clinical study documented that driver location and activation patterns in patients with LSpAF changes constantly. Furthermore, bi-atrial pathophysiology was demonstrated, which underscores the importance of treating both atria in LSpAF and the significant role that arrhythmogenic drivers outside the pulmonary veins seem to have in maintaining this complex arrhythmia.</p
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