273 research outputs found

    Arthrogryposis multiplex congenita (A.M.C.)

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    Thesis (M.D.)--Boston Universit

    The Role of Protein Arginine Methylation as Post-Translational Modification on Actin Cytoskeletal Components in Neuronal Structure and Function

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    The brain encompasses a complex network of neurons with exceptionally elaborated morphologies of their axonal (signal-sending) and dendritic (signal-receiving) parts. De novo actin filament formation is one of the major driving and steering forces for the development and plasticity of the neuronal arbor. Actin filament assembly and dynamics thus require tight temporal and spatial control. Such control is particularly effective at the level of regulating actin nucleation-promoting factors, as these are key components for filament formation. Arginine methylation represents an important post-translational regulatory mechanism that had previously been mainly associated with controlling nuclear processes. We will review and discuss emerging evidence from inhibitor studies and loss-of-function models for protein arginine methyltransferases (PRMTs), both in cells and whole organisms, that unveil that protein arginine methylation mediated by PRMTs represents an important regulatory mechanism in neuritic arbor formation, as well as in dendritic spine induction, maturation and plasticity. Recent results furthermore demonstrated that arginine methylation regulates actin cytosolic cytoskeletal components not only as indirect targets through additional signaling cascades, but can also directly control an actin nucleation-promoting factor shaping neuronal cells—a key process for the formation of neuronal networks in vertebrate brains

    Integrating Qualitative and Quantitative Methods to Evaluate Performance of the Brazilian Network for Continuous Global Navigation Satellite System (GNSS) Monitoring (RBMC)

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    We discuss a qualitative analysis of the efficiency of the Brazilian Network for Continuous Global Navigation Satellite System Monitoring (RBMC) using the Complex Holographic Assessment of Paradoxical Problems method (CHAP²), whose premise is the organization of intersubjectivity facilitated by the use of visual representation of structured knowledge (conceptual mapping) to increase the degree of consciousness to manage the paradoxes resulting from the complexity of living systems. We also describe a quantitative evaluation using Data Envelopment Analysis (DEA) allowing a ranking in terms of efficiency for further assessment by a professional of the area. The outcome of this study would be useful for IBGE (Brazilian Institute of Geography and Statistics) managers to be aware, for instance, of the suppliers and manufacturers of equipment available (receiver and geodetic antenna, Internet connection and constant supply of electricity) in efficient and ineffective stations, to guide new acquisitions, among other applications.

    Oxidative phosphorylation in human muscle in patients with ocular myopathy and after general anaesthesia

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    Abstract The fuel preference of human muscle mitochondria has been given. Substrates which are oxidized with low velocity cannot be used to detect defects in oxidative phosphorylation. After general anaesthesia, the oxygen uptake with the different substrates is much lower than after local analgesia. The latter was therefore used in the subsequent study. In 15 out of 18 patients with ocular myopathy, defects in oxidative phosporylation could be detected in isolated muscle mitochondria prepared from freshly biopsied tissue. Measurement of the activity of segments of the respiratory chain in homogenate from frozen muscle showed no, or minor defects. In two of these patients showing exercise intolerance, decreased oxidation of NAD+-linked substrates and apparently normal mitochondrial DNA, further study revealed deficiency of pyruvate dehydrogenase in a girl with ptosis and a high Km of complex I for NADH in a man. Both patients responded to vitamin therapy

    Ablation of Cypher, a PDZ-LIM domain Z-line protein, causes a severe form of congenital myopathy

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    Cypher is a member of a recently emerging family of proteins containing a PDZ domain at their NH2 terminus and one or three LIM domains at their COOH terminus. Cypher knockout mice display a severe form of congenital myopathy and die postnatally from functional failure in multiple striated muscles. Examination of striated muscle from the mutants revealed that Cypher is not required for sarcomerogenesis or Z-line assembly, but rather is required for maintenance of the Z-line during muscle function. In vitro studies demonstrated that individual domains within Cypher localize independently to the Z-line via interactions with α-actinin or other Z-line components. These results suggest that Cypher functions as a linker-strut to maintain cytoskeletal structure during contraction

    The BG News May 27, 1987

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    The BGSU campus student newspaper May 27, 1987. Volume 69 - Issue 122https://scholarworks.bgsu.edu/bg-news/5663/thumbnail.jp

    Exon skipping as a therapeutic strategy applied to an RYR1 mutation with pseudo-exon inclusion causing a severe core myopathy.

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    International audienceCentral core disease is a myopathy often arising from mutations in the type 1 ryanodine receptor (RYR1) gene, encoding the sarcoplasmic reticulum calcium release channel RyR1. No treatment is currently available for this disease. We studied the pathological situation of a severely affected child with two recessive mutations, which resulted in a massive reduction in the amount of RyR1. The paternal mutation induced the inclusion of a new in-frame pseudo-exon in RyR1 mRNA that resulted in the insertion of additional amino acids leading to the instability of the protein. We hypothesized that skipping this additional exon would be sufficient to restore RyR1 expression and to normalize calcium releases. We therefore developed U7-AON lentiviral vectors to force exon skipping on affected primary muscle cells. The efficiency of the exon skipping was evaluated at the mRNA level, at the protein level, and at the functional level using calcium imaging. In these affected cells, we observed a decreased inclusion of the pseudo-exon, an increased RyR1 protein expression, and a restoration of calcium releases of normal amplitude either upon direct RyR1 stimulation or in response to membrane depolarization. This study is the first demonstration of the potential of exon-skipping strategy for the therapy of central core disease, from the molecular to the functional level
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