232 research outputs found

    Pleosporales

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    One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae

    Morphological docking of secretory vesicles

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    Calcium-dependent secretion of neurotransmitters and hormones is essential for brain function and neuroendocrine-signaling. Prior to exocytosis, neurotransmitter-containing vesicles dock to the target membrane. In electron micrographs of neurons and neuroendocrine cells, like chromaffin cells many synaptic vesicles (SVs) and large dense-core vesicles (LDCVs) are docked. For many years the molecular identity of the morphologically docked state was unknown. Recently, we resolved the minimal docking machinery in adrenal medullary chromaffin cells using embryonic mouse model systems together with electron-microscopic analyses and also found that docking is controlled by the sub-membrane filamentous (F-)actin. Currently it is unclear if the same docking machinery operates in synapses. Here, I will review our docking assay that led to the identification of the LDCV docking machinery in chromaffin cells and also discuss whether identical docking proteins are required for SV docking in synapses

    Molecular Machines in the Synapse: Overlapping Protein Sets Control Distinct Steps in Neurosecretion

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    Activity regulated neurotransmission shapes the computational properties of a neuron and involves the concerted action of many proteins. Classical, intuitive working models often assign specific proteins to specific steps in such complex cellular processes, whereas modern systems theories emphasize more integrated functions of proteins. To test how often synaptic proteins participate in multiple steps in neurotransmission we present a novel probabilistic method to analyze complex functional data from genetic perturbation studies on neuronal secretion. Our method uses a mixture of probabilistic principal component analyzers to cluster genetic perturbations on two distinct steps in synaptic secretion, vesicle priming and fusion, and accounts for the poor standardization between different studies. Clustering data from 121 perturbations revealed that different perturbations of a given protein are often assigned to different steps in the release process. Furthermore, vesicle priming and fusion are inversely correlated for most of those perturbations where a specific protein domain was mutated to create a gain-of-function variant. Finally, two different modes of vesicle release, spontaneous and action potential evoked release, were affected similarly by most perturbations. This data suggests that the presynaptic protein network has evolved as a highly integrated supramolecular machine, which is responsible for both spontaneous and activity induced release, with a group of core proteins using different domains to act on multiple steps in the release process

    Protease-Sensitive Conformers in Broad Spectrum of Distinct PrPSc Structures in Sporadic Creutzfeldt-Jakob Disease Are Indicator of Progression Rate

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    The origin, range, and structure of prions causing the most common human prion disease, sporadic Creutzfeldt-Jakob disease (sCJD), are largely unknown. To investigate the molecular mechanism responsible for the broad phenotypic variability of sCJD, we analyzed the conformational characteristics of protease-sensitive and protease-resistant fractions of the pathogenic prion protein (PrPSc) using novel conformational methods derived from a conformation-dependent immunoassay (CDI). In 46 brains of patients homozygous for polymorphisms in the PRNP gene and exhibiting either Type 1 or Type 2 western blot pattern of the PrPSc, we identified an extensive array of PrPSc structures that differ in protease sensitivity, display of critical domains, and conformational stability. Surprisingly, in sCJD cases homozygous for methionine or valine at codon 129 of the PRNP gene, the concentration and stability of protease-sensitive conformers of PrPSc correlated with progression rate of the disease. These data indicate that sCJD brains exhibit a wide spectrum of PrPSc structural states, and accordingly argue for a broad spectrum of prion strains coding for different phenotypes. The link between disease duration, levels, and stability of protease-sensitive conformers of PrPSc suggests that these conformers play an important role in the pathogenesis of sCJD

    A meta-analysis of CAG (cytarabine, aclarubicin, G-CSF) regimen for the treatment of 1029 patients with acute myeloid leukemia and myelodysplastic syndrome

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    The regimen of cytarabine, aclarubicin and G-CSF (CAG) has been widely used in China and Japan for treatment of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We searched literature on CAG between 1995 and 2010 and performed a meta-analysis to determine its overall efficacy using a random-effects or fixed-effects model. Thirty five trials with a total of 1029 AML (n = 814) and MDS (n = 215) patients were included for analysis. The CR rate of AML (57.9%) was significantly higher than that of MDS (45.7%) (p < 0.01). No difference in CR was noted between the new (56.7%) and relapsed/refractory AML (60.1%) (p > 0.05). The CR rate was also significantly higher in patients with favorable (64.5%) and intermediate (69.6%) karyotypes than those with unfavorable one (29.5%) (p < 0.05). Remarkably, the CR rate of CAG was significantly higher than those of non-CAG regimens (odds ratio 2.43). CAG regimen was well tolerated, with cardiotoxicity in 2.3% and early death in 5.2% of the cases. In conclusion, CAG regimen was an effective and safe regimen for the treatment of AML, and may be more effective than non-CAG regimens. Randomized controlled trials are strongly recommended to evaluate its efficacy and safety in comparison with the current standard treatment

    Relativistic corrections in (gamma,N) knockout reactions

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    We develop a fully relativistic DWIA model for photonuclear reactions using the relativistic mean field theory for the bound state and the Pauli reduction of the scattering state which is calculated from a relativistic optical potential. Results for the 12C(gamma,p) and 16O(gamma,p) differential cross sections and photon asymmetries are displayed in a photon energy range between 60 and 257 MeV, and compared with nonrelativistic DWIA calculations. The effects of the spinor distortion and of the effective momentum approximation for the scattering state are discussed. The sensitivity of the model to different prescriptions for the one-body current operator is investigated. The off-shell ambiguities are large in (gamma,p) calculations, and even larger in (gamma,n) knockout.Comment: LaTeX2e, 18 pages, and 6 figure

    Metabolism-dependent bioaccumulation of uranium by Rhodosporidium toruloides isolated from the flooding water of a former uranium mine

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    Remediation of former uranium mining sites represents one of the biggest challenges worldwide that have to be solved in this century. During the last years, the search of alternative strategies involving environmentally sustainable treatments has started. Bioremediation, the use of microorganisms to clean up polluted sites in the environment, is considered one the best alternative. By means of culture-dependent methods, we isolated an indigenous yeast strain, KS5 (Rhodosporidium toruloides), directly from the flooding water of a former uranium mining site and investigated its interactions with uranium. Our results highlight distinct adaptive mechanisms towards high uranium concentrations on the one hand, and complex interaction mechanisms on the other. The cells of the strain KS5 exhibit high a uranium tolerance, being able to grow at 6 mM, and also a high ability to accumulate this radionuclide (350 mg uranium/g dry biomass, 48 h). The removal of uranium by KS5 displays a temperature- and cell viability-dependent process, indicating that metabolic activity could be involved. By STEM (scanning transmission electron microscopy) investigations, we observed that uranium was removed by two mechanisms, active bioaccumulation and inactive biosorption. This study highlights the potential of KS5 as a representative of indigenous species within the flooding water of a former uranium mine, which may play a key role in bioremediation of uranium contaminated sites.This work was supported by the Bundesministerium für Bildung und Forschung grand nº 02NUK030F (TransAqua). Further support took place by the ERDF-co-financed Grants CGL2012-36505 and 315 CGL2014-59616R, Ministerio de Ciencia e Innovación, Spain

    A Proposed Taxonomy of Anaerobic Fungi (Class Neocallimastigomycetes) Suitable for Large-Scale Sequence-Based Community Structure Analysis

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    Anaerobic fungi are key players in the breakdown of fibrous plant material in the rumen, but not much is known about the composition and stability of fungal communities in ruminants. We analyzed anaerobic fungi in 53 rumen samples from farmed sheep (4 different flocks), cattle, and deer feeding on a variety of diets. Denaturing gradient gel electrophoresis fingerprinting of the internal transcribed spacer 1 (ITS1) region of the rrn operon revealed a high diversity of anaerobic fungal phylotypes across all samples. Clone libraries of the ITS1 region were constructed from DNA from 11 rumen samples that had distinctly different fungal communities. A total of 417 new sequences were generated to expand the number and diversity of ITS1 sequences available. Major phylogenetic groups of anaerobic fungi in New Zealand ruminants belonged to the genera Piromyces, Neocallimastix, Caecomyces and Orpinomyces. In addition, sequences forming four novel clades were obtained, which may represent so far undetected genera or species of anaerobic fungi. We propose a revised phylogeny and pragmatic taxonomy for anaerobic fungi, which was tested and proved suitable for analysis of datasets stemming from high-throughput next-generation sequencing methods. Comparing our revised taxonomy to the taxonomic assignment of sequences deposited in the GenBank database, we believe that >29% of ITS1 sequences derived from anaerobic fungal isolates or clones are misnamed at the genus level
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