259 research outputs found

    Quantum dot-based multiphoton fluorescent pipettes for targeted neuronal electrophysiology

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    Targeting visually identified neurons for electrophysiological recording is a fundamental neuroscience technique; however, its potential is hampered by poor visualization of pipette tips in deep brain tissue. We describe quantum dot-coated glass pipettes that provide strong two-photon contrast at deeper penetration depths than those achievable with current methods. We demonstrated the pipettes' utility in targeted patch-clamp recording experiments and single-cell electroporation of identified rat and mouse neurons in vitro and in vivo

    Secondary education reform in Lesotho and Zimbabwe and the needs of rural girls: Pronouncements, policy and practice

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    Analysis of the educational needs of rural girls in Lesotho and Zimbabwe suggests a number of shortcomings in the current form of secondary education, and ways in which it might be modified so as to serve this sizeable group of students better. Several of the shortcomings, notably in relation to curricular irrelevance and excessive focus on examinations, have long been recognised, including by politicians. Yet political pronouncements are seldom translated into policy, and even where policy is formulated, reforms are seldom implemented in schools. This paper makes use of interviews with educational decision-makers in the two southern African countries and a range of documentary sources to explore why, despite the considerable differences between the two contexts, much needed educational reforms have been implemented in neither

    Bocepreviralapú hármas kezelés hatékonyságának és biztonságosságának retrospektív elemzése előrehaladott fibrosisstádiumú, hepatitis C-vírus 1-es genotípussal fertőzött, korábban sikertelenül kezelt magyar betegeknél

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    INTRODUCTION: During 2011 and 2013, 155 Hungarian hepatitis C genotype 1 infected patients, mostly with advanced liver fibrosis, who did not respond to prior peginterferon + ribavirin dual therapy, started boceprevir based triple therapy in an early access program. AIM AND METHOD: Efficacy and safety of the therapy was retrospectively assessed based on sustained virologic responses, as well as on frequency and type of serious adverse events and of those leading to therapy discontinuation. RESULTS: In an intent-to-treat analysis 39.4% patients (61/155) reached sustained virologic response. Amongst pervious relapsers, partial responders and null-responders 59.5%, 41.4 % and 22.9% (p<0.05 compared to the other two categories) reached sustained virologic response, respectively, while amongst non-cirrhotics and cirrhotics 52.5% and 31.3% (p<0.05 compared to the non-cirrhotics) achieved sutained virologic response, respectively. Six out of the 33 most difficult to cure patients (previous null responder and cirrhotic) have reached sustained virologic response (18.2%). Frequency of early discontinuations due to insufficient virologic response was 31.1%, while due to adverse event 10.3%. Reported frequency of serious adverse event was 9.8%. These events represented anemia, diarrhoea, depression, agranulocytosis, elevated aminotransferases, generalized dermatitis and severe gingivitis with loss of teeth, prolonged QT interval on ECG, generalized oedema and severe dyspnoea, uroinfection, exacerbation of Crohn's disease, Campylobacter pylori infection and unacceptable weakness and fatigue. Eight patients received transfusion, 4 patients erythropoietin and 1 granulocyte colony stimulating factor during therapy. No death has been reported. CONCLUSIONS: With boceprevir based triple therapy, one of the bests available in 2011-2013 in Hungary, a relevant proportion of hepatitis C infected patients with advanced liver fibrosis achieved sustained viral response. In this cohort, side-effects resembled those reported in registration studies, and resulted in therapy discontinuation with consequent treatment failure in a relevant number of patients. Efficacy and tolerability of boceprevir-based triple therapy are suboptimal, particularly in the most difficult to cure patient population. Orv. Hetil., 2016, 157(34), 1366-1374

    Nitric Oxide Signaling Modulates Synaptic Transmission during Early Postnatal Development

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    Early γ-aminobutyric acid mediated (GABAergic) synaptic transmission and correlated neuronal activity are fundamental to network formation; however, their regulation during early postnatal development is poorly understood. Nitric oxide (NO) is an important retrograde messenger at glutamatergic synapses, and it was recently shown to play an important role also at GABAergic synapses in the adult brain. The subcellular localization and network effect of this signaling pathway during early development are so far unexplored, but its disruption at this early age is known to lead to profound morphological and functional alterations. Here, we provide functional evidence—using whole-cell recording—that NO signaling modulates not only glutamatergic but also GABAergic synaptic transmission in the mouse hippocampus during the early postnatal period. We identified the precise subcellular localization of key elements of the underlying molecular cascade using immunohistochemistry at the light—and electron microscopic levels. As predicted by these morpho-functional data, multineuron calcium imaging in acute slices revealed that this NO-signaling machinery is involved also in the control of synchronous network activity patterns. We suggest that the retrograde NO-signaling system is ideally suited to fulfill a general presynaptic regulatory role and may effectively fine-tune network activity during early postnatal development, while GABAergic transmission is still depolarizing

    Dysfunction in the βII Spectrin-Dependent Cytoskeleton Underlies Human Arrhythmia.

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    Background: The cardiac cytoskeleton plays key roles in maintaining myocyte structural integrity in health and disease. In fact, human mutations in cardiac cytoskeletal elements are tightly linked with cardiac pathologies including myopathies, aortopathies, and dystrophies. Conversely, the link between cytoskeletal protein dysfunction in cardiac electrical activity is not well understood, and often overlooked in the cardiac arrhythmia field. Methods and Results: Here, we uncover a new mechanism for the regulation of cardiac membrane excitability. We report that βII spectrin, an actin-associated molecule, is essential for the post-translational targeting and localization of critical membrane proteins in heart. βII spectrin recruits ankyrin-B to the cardiac dyad, and a novel human mutation in the ankyrin-B gene disrupts the ankyrin-B/βII spectrin interaction leading to severe human arrhythmia phenotypes. Mice lacking cardiac βII spectrin display lethal arrhythmias, aberrant electrical and calcium handling phenotypes, and abnormal expression/localization of cardiac membrane proteins. Mechanistically, βII spectrin regulates the localization of cytoskeletal and plasma membrane/sarcoplasmic reticulum protein complexes that include the Na/Ca exchanger, RyR2, ankyrin-B, actin, and αII spectrin. Finally, we observe accelerated heart failure phenotypes in βII spectrin-deficient mice. Conclusions: Our findings identify βII spectrin as critical for normal myocyte electrical activity, link this molecule to human disease, and provide new insight into the mechanisms underlying cardiac myocyte biology
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