69 research outputs found

    Expanded analysis of high-grade astrocytoma with piloid features identifies an epigenetically and clinically distinct subtype associated with Neurofibromatosis Type 1

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    High-grade astrocytoma with piloid features (HGAP) is a recently recognized glioma type whose classification is dependent on its global epigenetic signature. HGAP is characterized by alterations in the mitogen-activated protein kinase (MAPK) pathway, often co-occurring with CDKN2A/B homozygous deletion and/or ATRX mutation. Experience with HGAP is limited and to better understand this tumor type, we evaluated an expanded cohort of patients (n = 144) with these tumors, as defined by DNA methylation array testing, with a subset additionally evaluated by next-generation sequencing (NGS). Among evaluable cases, we confirmed the high prevalence CDKN2A/B homozygous deletion, and/or ATRX mutations/loss in this tumor type, along with a subset showing NF1 alterations. Five of 93 (5.4%) cases sequenced harbored TP53 mutations and RNA fusion analysis identified a single tumor containing an NTRK2 gene fusion, neither of which have been previously reported in HGAP. Clustering analysis revealed the presence of three distinct HGAP subtypes (or groups = g) based on whole-genome DNA methylation patterns, which we provisionally designated as gNF1 (n = 18), g1 (n = 72), and g2 (n = 54) (median ages 43.5 years, 47 years, and 32 years, respectively). Subtype gNF1 is notable for enrichment with patients with Neurofibromatosis Type 1 (33.3%, p = 0.0008), confinement to the posterior fossa, hypermethylation in the NF1 enhancer region, a trend towards decreased progression-free survival (p = 0.0579), RNA processing pathway dysregulation, and elevated non-neoplastic glia and neuron cell content (p \u3c 0.0001 and p \u3c 0.0001, respectively). Overall, our expanded cohort broadens the genetic, epigenetic, and clinical phenotype of HGAP and provides evidence for distinct epigenetic subtypes in this tumor type

    ABCG1 maintains high-grade glioma survival in vitro and in vivo

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    The overall survival for adults with malignant glioma (glioblastoma) remains poor despite advances in radiation and chemotherapy. One of the mechanisms by which cancer cells develop relative resistance to treatment is through de-regulation of endoplasmic reticulum (ER) homeostasis. We have recently shown that ABCG1, an ATP-binding cassette transporter, maintains ER homeostasis and suppresses ER stress-induced apoptosis in low-grade glioma. Herein, we demonstrate that ABCG1 expression is increased in human adult glioblastoma, where it correlates with poor survival in individuals with the mesenchymal subtype. Leveraging a mouse model of mesenchymal glioblastoma (NPcis), shRNA-mediated Abcg1 knockdown (KD) increased CHOP ER stress protein expression and resulted in greater NPcis glioma cell death in vitro. Moreover, Abcg1 KD reduced NPcis glioma growth and increased mouse survival in vivo. Collectively, these results demonstrate that ABCG1 is critical for malignant glioma cell survival, and might serve as a future therapeutic target for these deadly brain cancers

    The cell of origin dictates the temporal course of neurofibromatosis-1 (Nf1) low-grade glioma formation.

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    Low-grade gliomas are one of the most common brain tumors in children, where they frequently form within the optic pathway (optic pathway gliomas; OPGs). Since many OPGs occur in the context of the Neurofibromatosis Type 1 (NF1) cancer predisposition syndrome, we have previously employed Nf1 genetically-engineered mouse (GEM) strains to study the pathogenesis of these low-grade glial neoplasms. In the light of the finding that human and mouse low-grade gliomas are composed of Olig2+ cells and that Olig2+ oligodendrocyte precursor cells (OPCs) give rise to murine high-grade gliomas, we sought to determine whether Olig2+ OPCs could be tumor-initiating cells for Nf1 optic glioma. Similar to the GFAP-Cre transgenic strain previously employed to generate Nf1 optic gliomas, Olig2+ cells also give rise to astrocytes in the murine optic nerve in vivo. However, in contrast to the GFAP-Cre strain where somatic Nf1 inactivation in embryonic neural progenitor/stem cells (Nf1flox/mut; GFAP-Cre mice) results in optic gliomas by 3 months of age in vivo, mice with Nf1 gene inactivation in Olig2+ OPCs (Nf1flox/mut; Olig2-Cre mice) do not form optic gliomas until 6 months of age. These distinct patterns of glioma latency do not reflect differences in the timing or brain location of somatic Nf1 loss. Instead, they most likely reflect the cell of origin, as somatic Nf1 loss in CD133+ neural progenitor/stem cells during late embryogenesis results in optic gliomas at 3 months of age. Collectively, these data demonstrate that the cell of origin dictates the time to tumorigenesis in murine optic glioma

    A public health response against Strongyloides stercoralis : time to look at soil-transmitted helminthiasis in full

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    Strongyloides stercoralis infections have a worldwide distribution with a global burden in terms of prevalence and morbidity that is largely ignored. A public health response against soil-transmitted helminth (STH) infections should broaden the strategy to include S. stercoralis and overcome the epidemiological, diagnostic, and therapeutic challenges that this parasite poses in comparison to Ascaris lumbricoides, Trichuris trichiura, and hookworms. The relatively poor sensitivity of single stool evaluations, which is further lowered when quantitative techniques aimed at detecting eggs are used, also complicates morbidity evaluations and adequate drug efficacy measurements, since S. stercoralis is eliminated in stools in a larval stage. Specific stool techniques for the detection of larvae of S. stercoralis, like Baermann's and Koga's agar plate, despite superiority over direct techniques are still suboptimal. New serologies using recombinant antigens and molecular-based techniques offer new hopes in those areas. The use of ivermectin rather than benzimidazoles for its treatment and the need to have curative regimens rather than lowering the parasite burden are also unique for S. stercoralis in comparison to the other STH due to its life cycle, which allows reproduction and amplification of the worm burden within the human host. The potential impact on STH of the benzimidazoles/ivermectin combinations, already used for control/elimination of lymphatic filariasis, should be further evaluated in public health settings. While waiting for more effective single-dose drug regimens and new sensitive diagnostics, the evidence and the tools already available warrant the planning of a common platform for STH and S. stercoralis control

    Design of a graphical and interactive interface for facilitating access to drug contraindications, cautions for use, interactions and adverse effects

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    <p>Abstract</p> <p>Background</p> <p>Drug iatrogeny is important but could be decreased if contraindications, cautions for use, drug interactions and adverse effects of drugs described in drug monographs were taken into account. However, the physician's time is limited during consultations, and this information is often not consulted. We describe here the design of "Mister VCM", a graphical interface based on the VCM graphical language, facilitating access to drug monographs. We also provide an assessment of the usability of this interface.</p> <p>Methods</p> <p>The "Mister VCM" interface was designed by dividing the screen into two parts: a graphical interactive one including VCM icons and synthetizing drug properties, a textual one presenting on demand drug monograph excerpts. The interface was evaluated over 11 volunteer general practitioners, trained in the use of "Mister VCM". They were asked to answer clinical questions related to fictitious randomly generated drug monographs, using a textual interface or "Mister VCM". When answering the questions, correctness of the responses and response time were recorded.</p> <p>Results</p> <p>"Mister VCM" is an interactive interface that displays VCM icons organized around an anatomical diagram of the human body with additional mental, etiological and physiological areas. Textual excerpts of the drug monograph can be displayed by clicking on the VCM icons. The interface can explicitly represent information implicit in the drug monograph, such as the absence of a given contraindication. Physicians made fewer errors with "Mister VCM" than with text (factor of 1.7; <it>p </it>= 0.034) and responded to questions 2.2 times faster (<it>p </it>< 0.001). The time gain with "Mister VCM" was greater for long monographs and questions with implicit replies.</p> <p>Conclusion</p> <p>"Mister VCM" seems to be a promising interface for accessing drug monographs. Similar interfaces could be developed for other medical domains, such as electronic patient records.</p
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