146 research outputs found

    Evaluation of Bleeding Disorders in Patients With Noonan Syndrome: A Systematic Review

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    Background: Noonan syndrome (NS) is an autosomal dominant genetic condition that has a number of clinical features, including bleeding diathesis and a number of hematological abnormalities including clotting factor deficiencies, von Willebrand disease and abnormal platelet count/function. Methods: We evaluated the frequency/types of bleeding disorders, and associated hematological laboratory findings, in patients with NS, using published data from 1965 to 2014. Results: Of 45 studies identified, 31 included data for 428 patients with NS. Of these patients, 43% had reported bleeding, 26% had no reported bleeding and no bleed data was reported for 31%. Most patients (90%) had bleeding-related laboratory test abnormalities, but only 194 (45%) had a confirmed diagnosis of a specific bleeding disorder. Abnormal laboratory tests included: prolonged prothrombin time, activated partial thromboplastin time, and other platelet-related disorders. Of the 194 patients with a confirmed diagnosis of a specific bleeding disorder, 153 (79%) had single clotting factor deficiencies, von Willebrand disease or platelet-related disorders, and 41 (21%) had multiple deficiencies including platelet-related disorders. Conclusion: As patients with NS can experience multiple bleeding disorders, including abnormal platelet function, clinical evaluations should be performed at diagnosis, after diagnosis, before any surgery is undertaken, and if patients become symptomatic

    Resistance from Afar: Distal Mutation V36M Allosterically Modulates the Active Site to Accentuate Drug Resistance in HCV NS3/4A Protease [preprint]

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    Hepatitis C virus rapidly evolves, conferring resistance to direct acting antivirals. While resistance via active site mutations in the viral NS3/4A protease has been well characterized, the mechanism for resistance of non-active site mutations is unclear. R155K and V36M often co-evolve and while R155K alters the electrostatic network at the binding site, V36M is more than 13 Angstrom away. In this study the mechanism by which V36M confers resistance, in the context of R155K, is elucidated with drug susceptibility assays, crystal structures, and molecular dynamics (MD) simulations for three protease inhibitors: telaprevir, boceprevir and danoprevir. The R155K and R155K/V36M crystal structures differ in the α-2 helix and E2 strand near the active site, with alternative conformations at M36 and side chains of active site residues D168 and R123, revealing an allosteric coupling, which persists dynamically in MD simulations, between the distal mutation and the active site. This allosteric modulation validates the network hypothesis and elucidates how distal mutations confer resistance through propagation of conformational changes to the active site

    The Molecular Basis of Drug Resistance against Hepatitis C Virus NS3/4A Protease Inhibitors

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    Hepatitis C virus (HCV) infects over 170 million people worldwide and is the leading cause of chronic liver diseases, including cirrhosis, liver failure, and liver cancer. Available antiviral therapies cause severe side effects and are effective only for a subset of patients, though treatment outcomes have recently been improved by the combination therapy now including boceprevir and telaprevir, which inhibit the viral NS3/4A protease. Despite extensive efforts to develop more potent next-generation protease inhibitors, however, the long-term efficacy of this drug class is challenged by the rapid emergence of resistance. Single-site mutations at protease residues R155, A156 and D168 confer resistance to nearly all inhibitors in clinical development. Thus, developing the next-generation of drugs that retain activity against a broader spectrum of resistant viral variants requires a comprehensive understanding of the molecular basis of drug resistance. In this study, 16 high-resolution crystal structures of four representative protease inhibitors - telaprevir, danoprevir, vaniprevir and MK-5172 - in complex with the wild-type protease and three major drug-resistant variants R155K, A156T and D168A, reveal unique molecular underpinnings of resistance to each drug. The drugs exhibit differential susceptibilities to these protease variants in both enzymatic and antiviral assays. Telaprevir, danoprevir and vaniprevir interact directly with sites that confer resistance upon mutation, while MK-5172 interacts in a unique conformation with the catalytic triad. This novel mode of MK-5172 binding explains its retained potency against two multi-drug-resistant variants, R155K and D168A. These findings define the molecular basis of HCV N3/4A protease inhibitor resistance and provide potential strategies for designing robust therapies against this rapidly evolving virus

    Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers

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    We study frequency dependent (FD) input-output schemes for signal-recycling interferometers, the baseline design of Advanced LIGO and the current configuration of GEO 600. Complementary to a recent proposal by Harms et al. to use FD input squeezing and ordinary homodyne detection, we explore a scheme which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are sub-optimal among all possible input-output schemes, provide a global noise suppression by the power squeeze factor, while being realizable by using detuned Fabry-Perot cavities as input/output filters. At high frequencies, the two schemes are shown to be equivalent, while at low frequencies our scheme gives better performance than that of Harms et al., and is nearly fully optimal. We then study the sensitivity improvement achievable by these schemes in Advanced LIGO era (with 30-m filter cavities and current estimates of filter-mirror losses and thermal noise), for neutron star binary inspirals, and for narrowband GW sources such as low-mass X-ray binaries and known radio pulsars. Optical losses are shown to be a major obstacle for the actual implementation of these techniques in Advanced LIGO. On time scales of third-generation interferometers, like EURO/LIGO-III (~2012), with kilometer-scale filter cavities, a signal-recycling interferometer with the FD readout scheme explored in this paper can have performances comparable to existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi

    Upper limits on the strength of periodic gravitational waves from PSR J1939+2134

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    The first science run of the LIGO and GEO gravitational wave detectors presented the opportunity to test methods of searching for gravitational waves from known pulsars. Here we present new direct upper limits on the strength of waves from the pulsar PSR J1939+2134 using two independent analysis methods, one in the frequency domain using frequentist statistics and one in the time domain using Bayesian inference. Both methods show that the strain amplitude at Earth from this pulsar is less than a few times 102210^{-22}.Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 200

    Search for gravitational wave bursts in LIGO's third science run

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    We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit

    HisAK70: Progress towards a vaccine against different forms of leishmaniosis

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    Background: Leishmania major and Leishmania infantum are among the main species that are responsible for cutaneous leishmaniosis (CL) and visceral leishmaniosis (VL), respectively. The leishmanioses represent the second-largest parasitic killer in the world after malaria. Recently, we succeeded in generating a plasmid DNA (pCMV-HISA70m2A) and demonstrated that immunized mice were protected against L. major challenge. The efficacy of the DNA-vaccine was further enhanced by the inclusion of KMP-11 antigen into the antibiotic-free plasmid pVAX1-asd. Methods: Here, we describe the use of a HisAK70 DNA-vaccine encoding seven Leishmania genes (H2A, H2B, H3, H4, A2, KMP11 and HSP70) for vaccination of mice to assess the induction of a resistant phenotype against VL and CL. Results: HisAK70 was successful in vaccinated mice, resulting in a high amount of efficient sterile hepatic granulomas associated with a hepatic parasite burden fully resolved in the VL model; and resulting in 100 % inhibition of parasite visceralization in the CL model. Conclusions: The results suggest that immunization with the HisAK70 DNA-vaccine may provide a rapid, suitable, and efficient vaccination strategy to confer cross-protective immunity against VL and CL.This work was partially supported by grants from the Spanish Ministry of Economy and Competitiveness (AGL2010-17394 and AGL2013-44100R) and PLATESA (P2013/ABI-2906) from the Comunidad de Madrid (Spain).Peer Reviewe

    Tratamientos psicológicos empíricamente apoyados para adultos: Una revisión selectiva

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    Antecedentes: los tratamientos psicológicos han mostrado su eficacia, efectividad y eficiencia para el abordaje de los trastornos mentales; no obstante, considerando el conocimiento científico generado en los últimos años, no se dispone de trabajos de actualización en español sobre cuáles son los tratamientos psicológicos con respaldo empírico. El objetivo fue realizar una revisión selectiva de los principales tratamientos psicológicos empíricamente apoyados para el abordaje de trastornos mentales en personas adultas. Método: se recogen niveles de evidencia y grados de recomendación en función de los criterios propuestos por el Sistema Nacional de Salud de España (en las Guías de Práctica Clínica) para diferentes trastornos psicológicos. Resultados: los resultados sugieren que los tratamientos psicológicos disponen de apoyo empírico para el abordaje de un amplio elenco de trastornos psicológicos. El grado de apoyo empírico oscila de bajo a alto en función del trastorno psicológico analizado. La revisión sugiere que ciertos campos de intervención necesitan una mayor investigación. Conclusiones: a partir de esta revisión selectiva, los profesionales de la psicología podrán disponer de información rigurosa y actualizada que les permita tomar decisiones informadas a la hora de implementar aquellos procedimientos psicoterapéuticos empíricamente fundamentados en función de las características de las personas que demandan ayuda. Background: Psychological treatments have shown their efficacy, effectiveness, and efficiency in dealing with mental disorders. However, considering the scientific knowledge generated in recent years, in the Spanish context, there are no updating studies about empirically supported psychological treatments. The main goal was to carry out a selective review of the main empirically supported psychological treatments for mental disorders in adults. Method: Levels of evidence and degrees of recommendation were collected based on the criteria proposed by the Spanish National Health System (Clinical Practice Guidelines) for different psychological disorders. Results: The results indicate that psychological treatments have empirical support for the approach to a wide range of psychological disorders. These levels of empirical evidence gathered range from low to high depending on the psychological disorder analysed. The review indicates the existence of certain fields of intervention that need further investigation. Conclusions: Based on this selective review, psychology professionals will be able to have rigorous, up-to-date information that allows them to make informed decisions when implementing empirically based psychotherapeutic procedures based on the characteristics of the people who require help

    Impact of Optimized Breastfeeding on the Costs of Necrotizing Enterocolitis in Extremely Low Birthweight Infants

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    To estimate risk of NEC for ELBW infants as a function of preterm formula and maternal milk (MM) intake and calculate the impact of suboptimal feeding on NEC incidence and costs
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