216 research outputs found

    Long term response to steroid therapy in Rasmussen encephalitis

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    SummaryRasmussen encephalitis (RE) is a severe and progressive focal epilepsy of unknown origin that leads to deterioration of motor and cognitive function. In a previous study, we described positive effect of high doses of steroids during the first year after the onset of RE. The objective of this study was to evaluate this therapy at long term.We reviewed 11 patients (7 girls and 4 boys) with RE of the right hemisphere (7) and the left (4) at a follow-up of 9±2 years. Age at onset of RE ranged from 2 to 14 years.Six patients had no benefit from steroid therapy and underwent hemispherotomy. Five had significant reduction of seizure frequency with disappearance of epilepsia partialis continua, and improved motor function. Of these, two died of unexpected sudden death 5 and 7 years after seizure control. Two others with initial response experienced progressive recurrence of seizures 1 to 4 years after the end of steroid therapy and required hemispherotomy. Finally, only one patient exhibited total cessation of seizures with steroids for 3 years, but seizures progressively recurred although the frequency was moderate.Our data confirm that although steroid treatment can be useful when given early in the course of RE, long term relapse can occur among the good responders requiring delayed hemispheric disconnection

    Inapproximability of maximal strip recovery

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    In comparative genomic, the first step of sequence analysis is usually to decompose two or more genomes into syntenic blocks that are segments of homologous chromosomes. For the reliable recovery of syntenic blocks, noise and ambiguities in the genomic maps need to be removed first. Maximal Strip Recovery (MSR) is an optimization problem proposed by Zheng, Zhu, and Sankoff for reliably recovering syntenic blocks from genomic maps in the midst of noise and ambiguities. Given dd genomic maps as sequences of gene markers, the objective of \msr{d} is to find dd subsequences, one subsequence of each genomic map, such that the total length of syntenic blocks in these subsequences is maximized. For any constant d2d \ge 2, a polynomial-time 2d-approximation for \msr{d} was previously known. In this paper, we show that for any d2d \ge 2, \msr{d} is APX-hard, even for the most basic version of the problem in which all gene markers are distinct and appear in positive orientation in each genomic map. Moreover, we provide the first explicit lower bounds on approximating \msr{d} for all d2d \ge 2. In particular, we show that \msr{d} is NP-hard to approximate within Ω(d/logd)\Omega(d/\log d). From the other direction, we show that the previous 2d-approximation for \msr{d} can be optimized into a polynomial-time algorithm even if dd is not a constant but is part of the input. We then extend our inapproximability results to several related problems including \cmsr{d}, \gapmsr{\delta}{d}, and \gapcmsr{\delta}{d}.Comment: A preliminary version of this paper appeared in two parts in the Proceedings of the 20th International Symposium on Algorithms and Computation (ISAAC 2009) and the Proceedings of the 4th International Frontiers of Algorithmics Workshop (FAW 2010

    Treatment of electrical status epilepticus in sleep : A pooled analysis of 575 cases

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    OBJECTIVE: Epileptic encephalopathy with electrical status epilepticus in sleep (ESES) is a pediatric epilepsy syndrome with sleep-induced epileptic discharges and acquired impairment of cognition or behavior. Treatment of ESES is assumed to improve cognitive outcome. The aim of this study is to create an overview of the current evidence for different treatment regimens in children with ESES syndrome. METHODS: A literature search using PubMed and Embase was performed. Articles were selected that contain original treatment data of patients with ESES syndrome. Authors were contacted for additional information. Individual patient data were collected, coded, and analyzed using logistic regression analysis. The three predefined main outcome measures were improvement in cognitive function, electroencephalography (EEG) pattern, and any improvement (cognition or EEG). RESULTS: The literature search yielded 1,766 articles. After applying inclusion and exclusion criteria, 112 articles and 950 treatments in 575 patients could be analyzed. Antiepileptic drugs (AEDs, n = 495) were associated with improvement (i.e., cognition or EEG) in 49% of patients, benzodiazepines (n = 171) in 68%, and steroids (n = 166) in 81%. Surgery (n = 62) resulted in improvement in 90% of patients. In a subgroup analysis of patients who were consecutively reported (585 treatments in 282 patients), we found improvement in a smaller proportion treated with AEDs (34%), benzodiazepines (59%), and steroids (75%), whereas the improvement percentage after surgery was preserved (93%). Possible predictors of improved outcome were treatment category, normal development before ESES onset, and the absence of structural abnormalities. SIGNIFICANCE: Although most included studies were small and retrospective and their heterogeneity allowed analysis of only qualitative outcome data, this pooled analysis suggests superior efficacy of steroids and surgery in encephalopathy with ESES

    Severe reversible cardiac failure after bortezomib treatment combined with chemotherapy in a non-small cell lung cancer patient: a case report

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    BACKGROUND: Bortezomib (Velcade(®)), a dipeptide boronate proteasome inhibitor, is a novel anti-cancer agent registered for multiple myeloma (MM). It has also shown promising clinical activity in non-small cell lung cancer (NSCLC). Clinical experience with bortezomib so far indicates that overall incidence of cardiac failure associated with bortezomib therapy remains incidental. Nevertheless, acute development or exacerbation of congestive cardiac failure has been associated with bortezomib treatment. CASE PRESENTATION: We present here a case of severe, but reversible, congestive cardiac failure in a lung cancer patient who had no prior cardiac history, after receiving an experimental treatment of bortezomib combined with chemotherapy. Elevated levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP), as retrospectively measured in archived serum samples, were suggestive of pre-existent (sub-clinical) left ventricular dysfunction. CONCLUSION: Based on literature, we hypothesize that baseline presence of sub clinical cardiomyopathy, characterized by a dysregulation of the ubiquitin-proteasome system, could have predisposed this patient for a cardiac side effect induced by systemic proteasome inhibition. Patients with heart disease or risk factors for it should be closely monitored when being submitted to treatment with proteasome inhibition therapy such as bortezomib. Caution is therefore warranted in lung cancer patients who often present with cardiac comorbidities

    More Natural Models of Electoral Control by Partition

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    "Control" studies attempts to set the outcome of elections through the addition, deletion, or partition of voters or candidates. The set of benchmark control types was largely set in the seminal 1992 paper by Bartholdi, Tovey, and Trick that introduced control, and there now is a large literature studying how many of the benchmark types various election systems are vulnerable to, i.e., have polynomial-time attack algorithms for. However, although the longstanding benchmark models of addition and deletion model relatively well the real-world settings that inspire them, the longstanding benchmark models of partition model settings that are arguably quite distant from those they seek to capture. In this paper, we introduce--and for some important cases analyze the complexity of--new partition models that seek to better capture many real-world partition settings. In particular, in many partition settings one wants the two parts of the partition to be of (almost) equal size, or is partitioning into more than two parts, or has groups of actors who must be placed in the same part of the partition. Our hope is that having these new partition types will allow studies of control attacks to include such models that more realistically capture many settings

    Pharmacological screening using an FXN-EGFP cellular genomic reporter assay for the therapy of Friedreich ataxia

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    Copyright @ 2013 Li et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Friedreich ataxia (FRDA) is an autosomal recessive disorder characterized by neurodegeneration and cardiomyopathy. The presence of a GAA trinucleotide repeat expansion in the first intron of the FXN gene results in the inhibition of gene expression and an insufficiency of the mitochondrial protein frataxin. There is a correlation between expansion length, the amount of residual frataxin and the severity of disease. As the coding sequence is unaltered, pharmacological up-regulation of FXN expression may restore frataxin to therapeutic levels. To facilitate screening of compounds that modulate FXN expression in a physiologically relevant manner, we established a cellular genomic reporter assay consisting of a stable human cell line containing an FXN-EGFP fusion construct, in which the EGFP gene is fused in-frame with the entire normal human FXN gene present on a BAC clone. The cell line was used to establish a fluorometric cellular assay for use in high throughput screening (HTS) procedures. A small chemical library containing FDA-approved compounds and natural extracts was screened and analyzed. Compound hits identified by HTS were further evaluated by flow cytometry in the cellular genomic reporter assay. The effects on FXN mRNA and frataxin protein levels were measured in lymphoblast and fibroblast cell lines derived from individuals with FRDA and in a humanized GAA repeat expansion mouse model of FRDA. Compounds that were established to increase FXN gene expression and frataxin levels included several anti-cancer agents, the iron-chelator deferiprone and the phytoalexin resveratrol.Muscular Dystrophy Association (USA), the National Health and Medical Research Council (Australia), the Friedreich’s Ataxia Research Alliance (USA), the Brockhoff Foundation (Australia), the Friedreich Ataxia Research Association (Australasia), Seek A Miracle (USA) and the Victorian Government’s Operational Infrastructure Support Program

    Generation and characterisation of Friedreich ataxia YG8R mouse fibroblast and neural stem cell models

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    This article has been made available through the Brunel Open Access Publishing Fund.Background: Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by GAA repeat expansion in the first intron of the FXN gene, which encodes frataxin, an essential mitochondrial protein. To further characterise the molecular abnormalities associated with FRDA pathogenesis and to hasten drug screening, the development and use of animal and cellular models is considered essential. Studies of lower organisms have already contributed to understanding FRDA disease pathology, but mammalian cells are more related to FRDA patient cells in physiological terms. Methodology/Principal Findings: We have generated fibroblast cells and neural stem cells (NSCs) from control Y47R mice (9 GAA repeats) and GAA repeat expansion YG8R mice (190+120 GAA repeats). We then differentiated the NSCs in to neurons, oligodendrocytes and astrocytes as confirmed by immunocytochemical analysis of cell specific markers. The three YG8R mouse cell types (fibroblasts, NSCs and differentiated NSCs) exhibit GAA repeat stability, together with reduced expression of frataxin and reduced aconitase activity compared to control Y47R cells. Furthermore, YG8R cells also show increased sensitivity to oxidative stress and downregulation of Pgc-1α and antioxidant gene expression levels, especially Sod2. We also analysed various DNA mismatch repair (MMR) gene expression levels and found that YG8R cells displayed significant reduction in expression of several MMR genes, which may contribute to the GAA repeat stability. Conclusions/Significance: We describe the first fibroblast and NSC models from YG8R FRDA mice and we confirm that the NSCs can be differentiated into neurons and glia. These novel FRDA mouse cell models, which exhibit a FRDA-like cellular and molecular phenotype, will be valuable resources to further study FRDA molecular pathogenesis. They will also provide very useful tools for preclinical testing of frataxin-increasing compounds for FRDA drug therapy, for gene therapy, and as a source of cells for cell therapy testing in FRDA mice. © 2014 Sandi et al

    Muscle inactivation of mTOR causes metabolic and dystrophin defects leading to severe myopathy

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    Mammalian target of rapamycin (mTOR) is a key regulator of cell growth that associates with raptor and rictor to form the mTOR complex 1 (mTORC1) and mTORC2, respectively. Raptor is required for oxidative muscle integrity, whereas rictor is dispensable. In this study, we show that muscle-specific inactivation of mTOR leads to severe myopathy, resulting in premature death. mTOR-deficient muscles display metabolic changes similar to those observed in muscles lacking raptor, including impaired oxidative metabolism, altered mitochondrial regulation, and glycogen accumulation associated with protein kinase B/Akt hyperactivation. In addition, mTOR-deficient muscles exhibit increased basal glucose uptake, whereas whole body glucose homeostasis is essentially maintained. Importantly, loss of mTOR exacerbates the myopathic features in both slow oxidative and fast glycolytic muscles. Moreover, mTOR but not raptor and rictor deficiency leads to reduced muscle dystrophin content. We provide evidence that mTOR controls dystrophin transcription in a cell-autonomous, rapamycin-resistant, and kinase-independent manner. Collectively, our results demonstrate that mTOR acts mainly via mTORC1, whereas regulation of dystrophin is raptor and rictor independent
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