2,422 research outputs found

    The N-terminal intrinsically disordered domain of mgm101p is localized to the mitochondrial nucleoid.

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    The mitochondrial genome maintenance gene, MGM101, is essential for yeasts that depend on mitochondrial DNA replication. Previously, in Saccharomyces cerevisiae, it has been found that the carboxy-terminal two-thirds of Mgm101p has a functional core. Furthermore, there is a high level of amino acid sequence conservation in this region from widely diverse species. By contrast, the amino-terminal region, that is also essential for function, does not have recognizable conservation. Using a bioinformatic approach we find that the functional core from yeast and a corresponding region of Mgm101p from the coral Acropora millepora have an ordered structure, while the N-terminal domains of sequences from yeast and coral are predicted to be disordered. To examine whether ordered and disordered domains of Mgm101p have specific or general functions we made chimeric proteins from yeast and coral by swapping the two regions. We find, by an in vivo assay in S.cerevisiae, that the ordered domain of A.millepora can functionally replace the yeast core region but the disordered domain of the coral protein cannot substitute for its yeast counterpart. Mgm101p is found in the mitochondrial nucleoid along with enzymes and proteins involved in mtDNA replication. By attaching green fluorescent protein to the N-terminal disordered domain of yeast Mgm101p we find that GFP is still directed to the mitochondrial nucleoid where full-length Mgm101p-GFP is targeted

    Primary pyogenic spondylitis following kyphoplasty: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Only ten cases of primary pyogenic spondylitis following vertebroplasty have been reported in the literature. To the best of our knowledge, we present the first reported case of primary pyogenic spondylitis and spondylodiscitis caused by kyphoplasty.</p> <p>Case presentation</p> <p>A 72-year old Caucasian man with an osteoporotic compression fracture of the first lumbar vertebra after kyphoplasty developed sensory incomplete paraplegia below the first lumbar vertebra. This was caused by myelon compression following pyogenic spondylitis with a psoas abscess. Computed tomography guided aspiration of the abscess cavity yielded group C <it>Streptococcus</it>. The psoas abscess was percutaneously drained and laminectomy and posterior instrumentation with an internal fixator from the eleventh thoracic vertebra to the fourth lumbar vertebra was performed. In a second operation, corpectomy of the first lumbar vertebra with cement removal and fusion from the twelfth thoracic vertebra to the second lumbar vertebra with a titanium cage was performed. Six weeks postoperatively, the patient was pain free with no neurologic deficits or signs of infection.</p> <p>Conclusion</p> <p>Pyogenic spondylitis is an extremely rare complication after kyphoplasty. When these patients develop recurrent back pain postoperatively, the diagnosis of pyogenic spondylitis must be considered.</p

    Critical fluctuations in the spin-orbit Mott Insulator Sr₃Irβ‚‚O₇

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    X-ray magnetic critical scattering measurements and specific heat measurements were performed on the perovskite iridate Sr₃Irβ‚‚O₇. We find that the magnetic interactions close to the NΒ΄eel temperature T_{N} = 283.4(2) K are threedimensional. This contrasts with previous studies which suggest two-dimensional behaviour like Sr₃IrOβ‚„. Violation of the Harris criterion (dΞ½ > 2) means that weak disorder becomes relevant. This leads a rounding of the antiferromagnetic phase transition at T_{N}, and modifies the critical exponents relative to the clean system. Specifically, we determine that the critical behaviour of Sr₃Irβ‚‚O₇ is representative of the diluted 3D Ising universality class

    Case Report: Disseminated, rifampicin resistant Mycobacterium bovis (BCG) infection in an immunocompromised child.

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    Background: Bacillus Calmette-GuΓ©rin (BCG) is a live-attenuated vaccine used world-wide for prevention of tuberculosis disease. In some immunocompromised hosts it has the potential to cause disease. As with other members of the M. tuberculosis complex it has the potential for acquiring drug resistance. Methods: We reviewed 10 years of paediatric clinical BCG strains referred to our clinical microbiology laboratory in Oxford where they underwent whole genome sequencing. We present a case series comparing clinical, pathogen genetic and pathogen phenotypic data, and consider the clinical implications. Results: We identified 15 BCG isolates from 8 children under 16 years old. Only one child had clinical disease with the other seven reported as local inoculation-site reactions. Case 1 suffered disseminated disease secondary to an undiagnosed IL-12/IFNΞ³ receptor defect and the BCG isolates evolved two different rifampicin resistance mutations. Across all 15 isolates, phenotypic resistance to each first line drug was seen. Conclusions: BCG is a safe and effective vaccine in children. Most clinical specimens in our series were not related to disease. However, in the context of rare pathogen-specific immunocompromise, BCG can cause pathology and acquire drug resistance under selection from therapy

    Prospective Investigation of Markers of Elevated Delirium Risk (PRIMED Risk) study protocol: a prospective, observational cohort study investigating blood and cerebrospinal fluid biomarkers for delirium and cognitive dysfunction in older patients [version 1; peer review: awaiting peer review]

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    BACKGROUND: Delirium is a common post-operative complication, particularly in older adults undergoing major or emergency procedures. It is associated with increased length of intensive care and hospital stay, post-operative mortality and subsequent dementia risk. Current methods of predicting delirium incidence, duration and severity have limitations. Investigation of blood and cerebrospinal fluid (CSF) biomarkers linked to delirium may improve understanding of the underlying pathophysiology, particularly with regard to the extent this is shared or distinct with underlying dementia. Together, these have the potential for development of better risk stratification tools and perioperative interventions. / METHODS: 200 patients over the age of 70 scheduled for surgery with routine spinal anaesthetic will be recruited from UK hospitals. Their cognitive and functional baseline status will be assessed pre-operatively by telephone. Time-matched CSF and blood samples will be taken at the time of surgery and analysed for known biomarkers of neurodegeneration and neuroinflammation. Patients will be assessed daily for delirium until hospital discharge and will have regular cognitive follow-up for two years. Primary outcomes will be change in modified Telephone Interview for Cognitive Status (TICS-m) score at 12 months and rate of change of TICS-m score. Delirium severity, duration and biomarker levels will be treated as exposures in a random effects linear regression models. PRIMED Risk has received regulatory approvals from Health Research Authority and London – South East Research Ethics Committee. / DISCUSSION: The main anticipated output from this study will be the quantification of biomarkers of acute and chronic contributors to cognitive impairment after surgery. In addition, we aim to develop better risk prediction models for adverse cognitive outcomes

    Hsp90 orchestrates transcriptional regulation by Hsf1 and cell wall remodelling by MAPK signalling during thermal adaptation in a pathogenic yeast

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    Acknowledgments We thank Rebecca Shapiro for creating CaLC1819, CaLC1855 and CaLC1875, Gillian Milne for help with EM, Aaron Mitchell for generously providing the transposon insertion mutant library, Jesus Pla for generously providing the hog1 hst7 mutant, and Cathy Collins for technical assistance.Peer reviewedPublisher PD

    Circularly Polarized X Rays as a Probe of Noncollinear Magnetic Order in Multiferroic TbMnO3 (vol 102, 237205, 2009)

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    Erratum: Circularly Polarized X Rays as a Probe of Noncollinear Magnetic Order in Multiferroic TbMnO3 [Phys. Rev. Lett. 102, 237205 (2009)

    Strain control of a bandwidth-driven spin reorientation in Ca₃Ruβ‚‚O₇

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    The layered-ruthenate family of materials possess an intricate interplay of structural, electronic and magnetic degrees of freedom that yields a plethora of delicately balanced ground states. This is exemplified by Ca3Ru2O7, which hosts a coupled transition in which the lattice parameters jump, the Fermi surface partially gaps and the spins undergo a 90∘ in-plane reorientation. Here, we show how the transition is driven by a lattice strain that tunes the electronic bandwidth. We apply uniaxial stress to single crystals of Ca3Ru2O7, using neutron and resonant x-ray scattering to simultaneously probe the structural and magnetic responses. These measurements demonstrate that the transition can be driven by externally induced strain, stimulating the development of a theoretical model in which an internal strain is generated self-consistently to lower the electronic energy. We understand the strain to act by modifying tilts and rotations of the RuO6 octahedra, which directly influences the nearest-neighbour hopping. Our results offer a blueprint for uncovering the driving force behind coupled phase transitions, as well as a route to controlling them
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