6,100 research outputs found

    FXN promoter silencing in the humanized mouse model of Friedreich Ataxia

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    Background - Friedreich ataxia is caused by an expanded GAA triplet-repeat sequence in intron 1 of the FXN gene that results in epigenetic silencing of the FXN promoter. This silencing mechanism is seen in patient-derived lymphoblastoid cells but it remains unknown if it is a widespread phenomenon affecting multiple cell types and tissues. Methodology / Principal Findings - The humanized mouse model of Friedreich ataxia (YG8sR), which carries a single transgenic insert of the human FXN gene with an expanded GAA triplet-repeat in intron 1, is deficient for FXN transcript when compared to an isogenic transgenic mouse lacking the expanded repeat (Y47R). We found that in YG8sR the deficiency of FXN transcript extended both upstream and downstream of the expanded GAA triplet-repeat, suggestive of deficient transcriptional initiation. This pattern of deficiency was seen in all tissues tested, irrespective of whether they are known to be affected or spared in disease pathogenesis, in both neuronal and non-neuronal tissues, and in cultured primary fibroblasts. FXN promoter function was directly measured via metabolic labeling of newly synthesized transcripts in fibroblasts, which revealed that the YG8sR mouse was significantly deficient in transcriptional initiation compared to the Y47R mouse. Conclusions / Significance- Deficient transcriptional initiation accounts for FXN transcriptional deficiency in the humanized mouse model of Friedreich ataxia, similar to patient-derived cells, and the mechanism underlying promoter silencing in Friedreich ataxia is widespread across multiple cell types and tissues.This research was supported by grants from the National Institutes of Health (R01 NS072418), and the Muscular Dystrophy Association to S.I.B. Y.K.C. is supported by a postdoctoral research fellowship from the Million Dollar Bike Ride Grant Program of the Orphan Disease Center at University of Pennsylvania. T.T.H. was supported by the American College of Medical Genetics Foundation. A.C.P. and M.G.M. were supported by the SURE and OSCTR programs at OUHSC, respectively

    Caractérisation physico-chimique de la gomme Sterculia de trois localités de la région de Tambacounda au Sénégal

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    La gomme sterculia est produite par Sterculia setigera Del. en Afrique. Ses propriétés physicochimiques changent suivant divers facteurs dont l’influence sur sa qualité a été peu étudiée. C’est dans cette perspective que l’humidité, le pH, le pouvoir gonflant et la viscosité de cette gomme ont été évalués au Sénégal (Daoudi, Malem niani et Bala). Les résultats ont montré que son humidité varie en fonction du phénotype (écorce claire ou foncée). Elle a été plus élevée sur la gomme de la période sèche-chaude à Daoudi mais elle n’a pas changé suivant le site après un an de conservation. Son pH a varié en fonction de l’interaction période de saignée- couleur de l’écorce à Malem Niani alors qu’à Daoudi il a varié suivant la période de saignée seulement. A Malem, son gonflement a aussi varié suivant l’interaction période de saignée-couleur de l’écorce. Après un an de conservation (température ambiante), son pouvoir gonflant a diminué dans tous les sites. Sa viscosité a été 3,5 fois plus élevée à Bala qu’à Daoudi et Malem Niani. Ces résultats ont permis d’acquérir de nouvelles connaissances et d’identifier Bala comme ayant la meilleure qualité de gomme par rapport aux deux autres sites.Mots clés: Acidité, Humidité, pouvoir de gonflement, Sterculia setigera Del., Tambacounda, viscosit&#233

    Ethics Standards (HRPP) and Public Partnership (PARTAKE) to Address Clinical Research Concerns in India: Moving Toward Ethical, Responsible, Culturally Sensitive, and Community-Engaging Clinical Research.

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    Like other emerging economies, India's quest for independent, evidence-based, and affordable healthcare has led to robust and promising growth in the clinical research sector, with a compound annual growth rate (CAGR) of 20.4% between 2005 and 2010. However, while the fundamental drivers and strengths are still strong, the past few years witnessed a declining trend (CAGR -16.7%) amid regulatory concerns, activist protests, and sponsor departure. And although India accounts for 17.5% of the world's population, it currently conducts only 1% of clinical trials. Indian and international experts and public stakeholders gathered for a 2-day conference in June 2013 in New Delhi to discuss the challenges facing clinical research in India and to explore solutions. The main themes discussed were ethical standards, regulatory oversight, and partnerships with public stakeholders. The meeting was a collaboration of AAHRPP (Association for the Accreditation of Human Research Protection Programs)-aimed at establishing responsible and ethical clinical research standards-and PARTAKE (Public Awareness of Research for Therapeutic Advancements through Knowledge and Empowerment)-aimed at informing and engaging the public in clinical research. The present article covers recent clinical research developments in India as well as associated expectations, challenges, and suggestions for future directions. AAHRPP and PARTAKE provide etiologically based solutions to protect, inform, and engage the public and medical research sponsors

    In vitro micrografting of Sterculia setigera Del.

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    An in vitro procedure micrografting of adult scions of Sterculia setigera was developed to overcome low rooting in adult shoot. Axenic micro shoots of 0.5 cm length taken from adult trees as scions were grafted on seedlings rootstocks cultured on MS medium. 100% success was obtained with micrografts using adult apex as scions. Upon three cycles of in vitro micrografting, rejuvenation capacities of S. setigera was recovered as shown by vigour, length and rooting of shoots grown from grafts cultured on MS medium compared to seedlings. Successful micrografts were transferred to plastic pots containing soil under mist house conditions before they were finally exposed to an external environment. 80% of the plantlets survived in the nursery.Keywords: Sterculia setigera, micrografting, rejuvenation, rootin

    The use of enoxaparin in Chinese patients undergoing percutaneous coronary intervention: observations on safety, efficacy, and pharmacokinetics from a pilot study

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    Predictive Value of auricular diagnosis on coronary heart disease

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    Author name used in this publication: Lorna Kwai-Ping SuenVersion of RecordPublishe

    Universality of pseudogap and emergent order in lightly doped Mott insulators

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    It is widely believed that high-temperature superconductivity in the cuprates emerges from doped Mott insulators. The physics of the parent state seems deceivingly simple: The hopping of the electrons from site to site is prohibited because their on-site Coulomb repulsion U is larger than the kinetic energy gain t. When doping these materials by inserting a small percentage of extra carriers, the electrons become mobile but the strong correlations from the Mott state are thought to survive; inhomogeneous electronic order, a mysterious pseudogap and, eventually, superconductivity appear. How the insertion of dopant atoms drives this evolution is not known, nor whether these phenomena are mere distractions specific to hole-doped cuprates or represent the genuine physics of doped Mott insulators. Here, we visualize the evolution of the electronic states of (Sr1-xLax)2IrO4, which is an effective spin-1/2 Mott insulator like the cuprates, but is chemically radically different. Using spectroscopic-imaging STM, we find that for doping concentration of x=5%, an inhomogeneous, phase separated state emerges, with the nucleation of pseudogap puddles around clusters of dopant atoms. Within these puddles, we observe the same glassy electronic order that is so iconic for the underdoped cuprates. Further, we illuminate the genesis of this state using the unique possibility to localize dopant atoms on topographs in these samples. At low doping, we find evidence for much deeper trapping of carriers compared to the cuprates. This leads to fully gapped spectra with the chemical potential at mid-gap, which abruptly collapse at a threshold of around 4%. Our results clarify the melting of the Mott state, and establish phase separation and electronic order as generic features of doped Mott insulators.Comment: This version contains the supplementary information and small updates on figures and tex

    Chocolate consumption and incident heart failure

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    BACKGROUND: We aimed to examine the association between chocolate intake and the risk of incident heart failure in a UK general population. We conducted a systematic review and meta-analysis to quantify this association. METHODS AND RESULTS: We used data from a prospective population-based study, the European Prospective Investigation into Cancer (EPIC)-Norfolk cohort. Chocolate intake was quantified based on a food frequency questionnaire obtained at baseline (1993-1997) and incident heart failure was ascertained up to March 2009. We supplemented the primary data with a systematic review and meta-analysis of studies which evaluated risk of incident heart failure with chocolate consumption. A total of 20,922 participants (53% women; mean age 58 ± 9 years) were included of whom 1101 developed heart failure during the follow up (mean 12.5 ± 2.7 years, total person years 262,291 years). After adjusting for lifestyle and dietary factors, we found 19% relative reduction in heart failure incidence in the top (up to 100 g/d) compared to the bottom quintile of chocolate consumption (HR 0.81 95%CI 0.66-0.98) but the results were no longer significant after controlling for comorbidities (HR 0.87 95%CI 0.71-1.06). Additional adjustment for potential mediators did not attenuate the results further. We identified five relevant studies including the current study (N = 75,408). The pooled results showed non-significant 19% relative risk reduction of heart failure incidence with higher chocolate consumption (HR 0.81 95%CI 0.66-1.01). CONCLUSIONS: Our results suggest that higher chocolate intake is not associated with subsequent incident heart failure.The EPIC-Norfolk study was supported by grants from the Medical Research Council and Cancer Research UK.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.numecd.2016.01.00

    The Age of the Galactic Disk

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    I review different methods devised to derive the age of the Galactic Disk, namely the Radio-active Decay (RD), the Cool White Dwarf Luminosity Function (CWDLF), old opne clusters (OOC) and the Color Magnitude Diagram (CMD) of the stars in the solar vicinity. I argue that the disk is likely to be 8-10 Gyr old. Since the bulk of globulars has an age around 13 Gyr, the possibility emerges that the Galaxy experienced a minimum of Star Formation at the end of the halo/bulge formation. This minimum might reflect the time at which the Galaxy started to acquire material to form the disk inside-out.Comment: 10 pages, 4 figure, invited review, in "The chemical evolution of the Milky Way : Stars vs Clusters, Vulcano (Italy), 20-24 September 199
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