48 research outputs found

    Pulmonary Arterial Stent Implantation in an Adult with Williams Syndrome

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    We report a 38-year-old patient who presented with pulmonary hypertension and right ventricular dysfunction due to pulmonary artery stenoses as a manifestation of Williams syndrome, mimicking chronic thromboembolic pulmonary hypertension. The patient was treated with balloon angioplasty and stent implantation. Short-term follow-up showed a good clinical result with excellent patency of the stents but early restenosis of the segments in which only balloon angioplasty was performed. These stenoses were subsequently also treated successfully by stent implantation. Stent patency was observed 3 years after the first procedure

    Construction and in vivo assembly of a catalytically proficient and hyperthermostable de novo enzyme

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    Although catalytic mechanisms in natural enzymes are well understood, achieving the diverse palette of reaction chemistries in re-engineered native proteins has proved challenging. Wholesale modification of natural enzymes is potentially compromised by their intrinsic complexity, which often obscures the underlying principles governing biocatalytic efficiency. The maquette approach can circumvent this complexity by combining a robust de novo designed chassis with a design process that avoids atomistic mimicry of natural proteins. Here, we apply this method to the construction of a highly efficient, promiscuous, and thermostable artificial enzyme that catalyzes a diverse array of substrate oxidations coupled to the reduction of H2O2. The maquette exhibits kinetics that match and even surpass those of certain natural peroxidases, retains its activity at elevated temperature and in the presence of organic solvents, and provides a simple platform for interrogating catalytic intermediates common to natural heme-containing enzymes

    Sexual and postmating reproductive isolation between allopatric Drosophila montana populations suggest speciation potential

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    This work was funded by a European Commission Research Training Grant RTN2-2001-00049, the Centre of Excellence for Evolutionary Research at the University of Jyväskylä and a Marie Curie Initial Training Network, ‘Understanding the evolutionary origin of biological diversity’ (ITN-2008-213780 SPECIATION)Background: Widely distributed species with populations adapted to different environmental conditions can provide valuable opportunities for tracing the onset of reproductive incompatibilities and their role in the speciation process. Drosophila montana, a D. virilis group species found in high latitude boreal forests in Nearctic and Palearctic regions around the globe, could be an excellent model system for studying the early stages of speciation, as a wealth of information concerning this species' ecology, mating system, life history, genetics and phylogeography is available. However, reproductive barriers between populations have hereto not been investigated. Results: We report both pre- and postmating barriers to reproduction between flies from European (Finnish) and North American (Canadian) populations of Drosophila montana. Using a series of mate-choice designs, we show that flies from these two populations mate assortatively (i.e., exhibit significant sexual isolation) while emphasizing the importance of experimental design in these kinds of studies. We also assessed potential postmating isolation by quantifying egg and progeny production in intra-and interpopulation crosses and show a significant one-way reduction in progeny production, affecting both male and female offspring equally. Conclusion: We provide evidence that allopatric D. montana populations exhibit reproductive isolation and we discuss the potential mechanisms involved. Our data emphasize the importance of experimental design in studies on premating isolation between recently diverged taxa and suggest that postmating barriers may be due to postcopulatory-prezygotic mechanisms. D. montana populations seem to be evolving multiple barriers to gene flow in allopatry and our study lays the groundwork for future investigations of the genetic and phenotypic mechanisms underlying these barriers.Publisher PDFPeer reviewe

    Radiographic manifestations of eosinophilic gastroenteritis

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    Eosinophilic gastroenteritis (EG) is a rare inflammatory disease of unknown etiology, characterized by focal or diffuse eosinophilic infiltration of the gastrointestinal tract. Although little over 250 cases of EG have been reported in the literature, EG is probably more common than reports in the literature would indicate. A retrospective review of 25 patients with EG along with a review of the literature was done to identify clinical, laboratory, radiographic, and therapeutic features. An allergic disorder was present in 14 (56%) and a peripheral eosinophilia was present in 24 (96%) of our patients. The most common radiographic manifestations of the stomach and small bowel included stenosis and fold thickening, respectively. Thirteen patients had esophageal involvement, with the esophageal stricture being the most common abnormality found in these patients. Steroids produced a good therapeutic result in most patients; the remaining patients responded to cromolyn and/or surgery.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48145/1/261_2005_Article_BF01213260.pd
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