222 research outputs found

    Competing superconducting and magnetic order parameters and field-induced magnetism in electron doped Ba(Fe1x_{1-x}Cox_{x})2_{2}As2_{2}

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    We have studied the magnetic and superconducting properties of Ba(Fe0.95_{0.95}Co0.05_{0.05})2_{2}As2_{2} as a function of temperature and external magnetic field using neutron scattering and muon spin rotation. Below the superconducting transition temperature the magnetic and superconducting order parameters coexist and compete. A magnetic field can significantly enhance the magnetic scattering in the superconducting state, roughly doubling the Bragg intensity at 13.5 T. We perform a microscopic modelling of the data by use of a five-band Hamiltonian relevant to iron pnictides. In the superconducting state, vortices can slow down and freeze spin fluctuations locally. When such regions couple they result in a long-range ordered antiferromagnetic phase producing the enhanced magnetic elastic scattering in agreement with experiments.Comment: 9 pages, 6 figure

    Effect of Platelet-activating Factor on in vitro and in vivo Interleukin-6 Production

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    The aim of the present study was to investigate the possible effect of platelet-activating factor (PAF), by comparison with interleukin-1β and polyriboinositic/polyribocytidylic (poly I–C) acid, on IL-6 production by L 929 mouse fibroblasts. At concentrations above 1 μM PAF, the production of IL-6 by mouse fibroblasts was enhanced in a dose dependent fashion. At 5 μM PAF, the peak increase (60.1 ± 19.4 U/ml) was similar to that induced by 50 μg/ml poly I–C (60.0 ± 35.0 U/ml) and higher than the one evoked by 100 U/ml IL-1β (3.8 ± 1.8 U/ml). The increase of 11-6 activity induced by 5 μM PAF was maximal after a 22 h incubation period with L 929 cells. Lyso-PAF (5 μM) also increased IL-6 activity from fibroblasts to a similar extent compared with 5 μM PAF. In addition, the IL-6 activity induced by 5 μM PAF was still observed when the specific PAF antagonist, BN 52021 (10 μM), was added to the incubation medium of L 929 cells. The result suggests that the production of IL-6 by L 929 cells evoked by PAF in vitro is not receptor mediated. The in vivo effect of PAF on IL-6 production was also investigated in the rat. Two hours after intravenous injection of PAF (2 to 4 μg/kg), a dramatic increase of IL-6 activity in rat serum was observed, this effect being dose dependent. The increase of IL-6 induced by 3 μg/kg PAF was not observed when the animals were treated with the PAF antagonist, BN 52021 (1 to 60 mg/kg0. These results demonstrate that PAF modulates IL-6 production and that the in vivo effect is receptor mediated

    Isolation of a novel thermostable dehydrochlorinase (LinA) from a soil metagenome

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    Hexachlorocyclohexane dehydrochlorinase (LinA) mediates first step of aerobic degradation of a chlorinated insecticide γ-hexachlorocyclohexane (γ-HCH). In this study, we describe characterization of a novel variant (LinA-type2) that is distinct from reported LinAs and is substantially more thermostable than archetypal LinA-UT26. LinA-type2 remains active even after 8 h of incubation at 45 °C, when nearly 50% activity of LinA-UT26 is lost after incubation for 60 min at the same temperature. Circular dichroism analysis revealed that secondary structures of LinA-UT26 and LinA-type2 are similar, but their Tm was 45 and 65 °C, respectively. Thermostability of LinA-type2 makes it suitable for bioreactors where allowance for higher temperatures can be of advantage

    Bronchial responses to substance P after antigen challenge in the guinea-pig: in vivo and in vitro studies

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    The effect of antigen challenge on the airway responses to substance P and on the epithelial neutral endopeptidase (NEP) activity was investigated in aerosol sensitized guinea-pigs. In vivo, bronchial responses to aerosolized substance P were similar to the responses observed in antigen-challenged guinea-pigs and in the control groups. In contrast, when the guinea-pigs were pretreated with the NEP inhibitor, phosphoramidon, a significant increase in the airway responses to substance P was observed after antigen challenge in vivo. However, in vitro, the contractile responses of the tracheal smooth muscle to substance P were similar between groups of guinea-pigs, in respect to the presence or absence of the epithelium and/or phosphoramidon. Histological studies showed an accumulation of eosinophils in the tracheal submucosa after antigen challenge and intact epithelial cells. These results show that in vivo bronchial hyperresponsiveness to substance P after antigen challenge in the guinea-pig is not associated with increased responses of the smooth muscle to exogenous SP in vitro. In addition, the results with phosphoramidon suggest that loss of NEP activity cannot account for the in vivo bronchial hyperresponsiveness to substance P presently observed

    Competing superconducting and magnetic order parameters and field-induced magnetism in electron-doped \mathrm{Ba}{({\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x})}_{2}{\mathrm{As}}_{2}

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    We have studied the magnetic and superconducting properties of Ba(Fe0.95Co0.05)2As2 as a function of temperature and external magnetic field using neutron scattering and muon spin rotation. Below the superconducting transition temperature the magnetic and superconducting order parameters coexist and compete. A magnetic field can significantly enhance the magnetic scattering in the superconducting state, roughly doubling the Bragg intensity at 13.5 T. We perform a microscopic modeling of the data by use of a five-band Hamiltonian relevant to iron pnictides. In the superconducting state, vortices can slow down and freeze spin fluctuations locally. When such regions couple they result in a long-range ordered antiferromagnetic phase producing the enhanced magnetic elastic scattering in agreement with experiments

    Parálisis idiopática del nervio hipogloso. Descripción de un caso.

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    Introduction: Hypoglossal nerve palsy is a rare mononeuropathy. The most common etiologies are tumor, traumatic, cerebral ischemic and iatrogenic causes. Description: We present a man with idiopathic hypoglossal nerve neuropathy. The patient's age, the presence of vascular risk factors and cerebral microangiopathy, and the clinical evolution leads us to discussion about the possibility of a ischemic or diabetic mononeuropathy as the etiology of the deficit. Discussion: In previous published series of idiopathic hypoglossal nerve palsy, the age of presentation is between 20 and 45 years and the patients have a favorable evolution. The pathophysiological mechanism could be similar to Bell's palsy. In our patient the physical examination and the complementary studies were normal, diagnose the deficit as idiopathic hypoglossal nerve palsy. However, due to patient's age, the presence of multiple vascular risk factors, cerebral microangiopathy and the persistence of the symptoms, we consider the existence of a local ischemic or diabetic damage as the cause of the mononeuropathy presented, and we think that the physiopathological mechanism could be similar to other mononeuropathies, such as III or VI cranial nerve palsy. Conclusion: We present an idiopathic hypoglossal nerve palsy, but due to characteristics of our patient, we discuss an ischemic or diabetic cause of the deficit.Introducción: La parálisis del nervio hipogloso es una mononeuropatía poco fre-cuente. Las etiologías más habituales son la tumoral, la traumática, la isquémica cere-bral y la iatrogénica, Descripción: Presentamos el caso de un paciente con neuropa-tía idiopática del nervio hipogloso, en el que por edad, la presencia de factores de riesgo vascular, la microangiopaía cerebral y la evolución nos lleva a discutir acerca de la posibilidad de que se trate de una mononeuropatía isquémica o diabética como etiología del déficit. Discusión: En estudios publicados de parálisis idiopáticas del nervio hipogloso la edad de presentación se sitúa entre los 20 y 45 años y tienen una evolución y recuperación favorable, atribuyéndole un mecanismo fisiopatológico similar al de la paralisis de Bell. En nuestro caso la exploración física y las pruebas complementarias realizadas no mostraron etiología del déficit, encontrándonos ante un nuevo caso de parálisis idiopática del nervio hipogloso. Sin embargo por la edad del paciente, la presencia de múltiples factores de riesgo vascular, la microangiopía cerebral y la persistencia de la sintomatología nos hace plantear la existencia de un mecanismo local, isquémico o diabético, como causa de la mononeuropatía presen-tada y pensar que nos podemos encontrar ante un mecanismo fisiopatológico similar al producido en otras mononeuropatías, como la del III o VI par craneal. Conclusión: Presentamos una parálisis del nervio hipogloso idiopática, que por las característi-cas de nuestro paciente nos hace pensar y discuti una posible etiología isquémica o diabética del déficit

    MicroRNAs in cardiac arrhythmia: DNA sequence variation of MiR-1 and MiR-133A in long QT syndrome.

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    Long QT syndrome (LQTS) is a genetic cardiac condition associated with prolonged ventricular repolarization, primarily a result of perturbations in cardiac ion channels, which predisposes individuals to life-threatening arrhythmias. Using DNA screening and sequencing methods, over 700 different LQTS-causing mutations have been identified in 13 genes worldwide. Despite this, the genetic cause of 30-50% of LQTS is presently unknown. MicroRNAs (miRNAs) are small (∼ 22 nucleotides) noncoding RNAs which post-transcriptionally regulate gene expression by binding complementary sequences within messenger RNAs (mRNAs). The human genome encodes over 1800 miRNAs, which target about 60% of human genes. Consequently, miRNAs are likely to regulate many complex processes in the body, indeed aberrant expression of various miRNA species has been implicated in numerous disease states, including cardiovascular diseases. MiR-1 and MiR-133A are the most abundant miRNAs in the heart and have both been reported to regulate cardiac ion channels. We hypothesized that, as a consequence of their role in regulating cardiac ion channels, genetic variation in the genes which encode MiR-1 and MiR-133A might explain some cases of LQTS. Four miRNA genes (miR-1-1, miR-1-2, miR-133a-1 and miR-133a-2), which encode MiR-1 and MiR-133A, were sequenced in 125 LQTS probands. No genetic variants were identified in miR-1-1 or miR-133a-1; but in miR-1-2 we identified a single substitution (n.100A> G) and in miR-133a-2 we identified two substitutions (n.-19G> A and n.98C> T). None of the variants affect the mature miRNA products. Our findings indicate that sequence variants of miR-1-1, miR-1-2, miR-133a-1 and miR-133a-2 are not a cause of LQTS in this cohort

    In search for comparability: the PECUNIA reference unit costs for health and social care services in Europe

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    Improving the efficiency of mental healthcare service delivery by learning from international best-practice examples requires valid data, including robust unit costs, which currently often lack cross-country comparability. The European ProgrammE in Costing, resource use measurement and outcome valuation for Use in multi-sectoral National and International health economic evaluAtions (PECUNIA) aimed to harmonize the international unit cost development. This article presents the methodology and set of 36 externally validated, standardized reference unit costs (RUCs) for five health and social care services (general practitioner, dentist, help-line, day-care center, nursing home) in Austria, England, Germany, Hungary, The Netherlands, and Spain based on unambiguous service definitions using the extended DESDE PECUNIA coding framework. The resulting PECUNIA RUCs are largely comparable across countries, with any causes for deviations (e.g., country-specific scope of services) transparently documented. Even under standardized methods, notable limitations due to data-driven divergences in key costing parameters remain. Increased cross-country comparability by adopting a uniform methodology and definitions can advance the quality of evidence-based policy guidance derived from health economic evaluations. The PECUNIA RUCs are available free of charge and aim to significantly improve the quality and feasibility of future economic evaluations and their transferability across mental health systems

    A rare SNP in pre-miR-34a is associated with increased levels of miR-34a in pancreatic beta cells.

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    Open Access Article.Changes in the levels of specific microRNAs (miRNAs) can reduce glucose-stimulated insulin secretion and increase beta-cell apoptosis, two causes of islet dysfunction and progression to type 2 diabetes. Studies have shown that single nucleotide polymorphisms (SNPs) within miRNA genes can affect their expression. We sought to determine whether miRNAs, with a known role in beta-cell function, possess SNPs within the pre-miRNA structure which can affect their expression. Using published literature and dbSNP, we aimed to identify miRNAs with a role in beta-cell function that also possess SNPs within the region encoding its pre-miRNA. Following transfection of plasmids, encoding the pre-miRNA and each allele of the SNP, miRNA expression was measured. Two rare SNPs located within the pre-miRNA structure of two miRNA genes important to beta-cell function (miR-34a and miR-96) were identified. Transfection of INS-1 and MIN6 cells with plasmids encoding pre-miR-34a and the minor allele of rs72631823 resulted in significantly (p < 0.05) higher miR-34a expression, compared to cells transfected with plasmids encoding the corresponding major allele. Similarly, higher levels were also observed upon transfection of HeLa cells. Transfection of MIN6 cells with plasmids encoding pre-miR-96 and each allele of rs41274239 resulted in no significant differences in miR-96 expression. A rare SNP in pre-miR-34a is associated with increased levels of mature miR-34a. Given that small changes in miR-34a levels have been shown to cause increased levels of beta-cell apoptosis this finding may be of interest to studies looking at determining the effect of rare variants on type 2 diabetes susceptibility

    Three deaf mice: mouse models for TECTA-based human hereditary deafness reveal domain-specific structural phenotypes in the tectorial membrane

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    Tecta is a modular, non-collagenous protein of the tectorial membrane, an extracellular matrix of the cochlea essential for normal hearing. Missense mutations in Tecta cause dominant forms of nonsyndromic deafness and a genotype-phenotype correlation has been reported in humans, with mutations in different Tecta domains causing mid- or high-frequency hearing impairments that are either stable or progressive. Three mutant mice were created as models for human Tecta mutations; the TectaL1820F, G1824D/+ mouse for zona pellucida (ZP) domain mutations causing stable mid-frequency hearing loss in a Belgian family, the TectaC1837G/+ mouse for a ZP-domain mutation underlying progressive mid-frequency hearing loss in a Spanish family, and the TectaC1619S/+ mouse for a zonadhesin-like (ZA) domain mutation responsible for progressive, high-frequency hearing loss in a French family. Mutations in the ZP and ZA domains generate distinctly different changes in the structure of the tectorial membrane. ABR thresholds in the 8-40 kHz range are elevated by 30-40 dB in the ZP-domain mutants, whilst those in the ZA-domain mutant are elevated by 20-30 dB. The phenotypes are stable and no evidence has been found for a progressive deterioration in tectorial membrane structure or auditory function. Despite elevated auditory thresholds, the Tecta mutant mice all exhibit an enhanced tendency to have audiogenic seizures in response to white noise stimuli at low sound pressure levels (≤84 dB SPL), revealing a previously unrecognised consequence of Tecta mutations. These results, together with those from previous studies, establish an allelic series for Tecta unequivocally demonstrating an association between genotype and phenotype
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