2,130 research outputs found
Phosphorylation of Subunit Proteins of Intermediate Filaments from Chicken Muscle and Nonmuscle Cells
The phosphorylation of the subunit proteins of intermediate (10-nm) filaments has been investigated in chicken muscle and nonmuscle cells by using a two-dimensional gel electrophoresis system. Desmin, the 50,000-dalton subunit protein of the intermediate filaments of muscle, had previously been shown to exist as two major isoelectric variants--alpha and ß --in smooth, skeletal, and cardiac chicken muscle. Incubation of skeletal and smooth muscle tissue with 32PO4{}3- reveals that the acidic variant, alpha -desmin, and three other desmin variants are phosphorylated in vivo and in vitro. Under the same conditions, minor components of alpha - and ß -tropomyosin from skeletal muscle, but not smooth muscle, are also phosphorylated. Both the phosphorylated desmin variants and the nonphosphorylated ß -desmin variant remain insoluble under conditions that solubilize actin and myosin filaments, but leave Z-discs and intermediate filaments insoluble. Primary cultures of embryonic chicken muscle labeled with 32PO4{}3- possess, in addition to the desmin variants described above, a major nonphosphorylated and multiple phosphorylated variants of the 52,000-dalton, fibroblast-type intermediate filament protein (IFP). Filamentous cytoskeletons, prepared from primary myogenic cultures by Triton X-100 extraction, contain actin and all of the phosphorylated and nonphosphorylated variants of both desmin and the IFP. Similarly, these proteins are the major components of the caps of aggregated 10-nm filaments isolated from the same cell cultures previously exposed to Colcemid. These results demonstrate that a nonphosphorylated and several phosphorylated variants of desmin and IFP are present in assembled structures in muscle and nonmuscle cells
Rocaglates induce gain-of-function alterations to eIF4A and eIF4F
Rocaglates are a diverse family of biologically active molecules that have gained tremendous interest in recent years due to their promising activities in pre-clinical cancer studies. As a result, this family of compounds has been significantly expanded through the development of efficient synthetic schemes. However, it is unknown whether all of the members of the rocaglate family act through similar mechanisms of action. Here, we present a comprehensive study comparing the biological activities of >200 rocaglates to better understand how the presence of different chemical entities influences their biological activities. Through this, we find that most rocaglates preferentially repress the translation of mRNAs containing purine-rich 5' leaders, but certain rocaglates lack this bias in translation repression. We also uncover an aspect of rocaglate mechanism of action in which the pool of translationally active eIF4F is diminished due to the sequestration of the complex onto RNA.P50 GM067041 - NIGMS NIH HHS; R24 GM111625 - NIGMS NIH HHS; R35 GM118173 - NIGMS NIH HHSPublished versio
Effects of anthropogenic emissions on the molecular composition of urban organic aerosols: An ultrahigh resolution mass spectrometry study
Identification of the organic composition of atmospheric aerosols is necessary to develop effective air pollution mitigation strategies. However, the majority of the organic aerosol mass is poorly characterized and its detailed analysis is a major analytical challenge. In this study, we applied state-of-the-art direct infusion nano-electrospray (nanoESI) ultrahigh resolution mass spectrometry (UHRMS) and liquid chromatography ESI Quadrupole Time-of-Flight (Q-TOF) MS for the analysis of the organic fraction of fine particulate matter (PM2.5) collected at an urban location in Cork, Ireland. Comprehensive mass spectral data evaluation methods (e.g., Kendrick Mass Defect and Van Krevelen) were used to identify compound classes and mass distributions of the detected species. Up to 850 elemental formulae were identified in negative mode nanoESI-UHR-MS. Nitrogen and/or sulphur containing organic species contributed up to 40% of the total identified formulae and exhibited strong diurnal variations suggesting the importance of night-time NO3 chemistry at the site. The presence of a large number of oxidised aromatic and nitroaromatic compounds in the samples indicated a strong anthropogenic influence, i.e., from traffic emissions and domestic solid fuel (DSF) burning. Most of the identified biogenic secondary organic aerosol (SOA) compounds are later-generation nitrogen- and sulphur-containing products, indicating that SOA composition is strongly affected by anthropogenic species such as NOx and SO2. Unsaturated and saturated C12–C20 fatty acids were found to be the most abundant homologs with a composition reflecting a primary marine origin. The results of this work demonstrate that the studied site is a very complex environment affected by a variety of anthropogenic activities and natural sources.Research at the University of Cambridge was supported by a Marie Curie Intra-European
fellowship (project # 254319) and the European Research Council (ERC starting grant 279405).This is the accepted version. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S1352231014001472
Combination fluticasone and salmeterol versus fixed dose combination budesonide and formoterol for chronic asthma in adults and children
BackgroundCombination therapies are frequently recommended as maintenance therapy for people with asthma, whose disease is not adequately controlled with inhaled steroids. Fluticasone/salmeterol (FP/SAL) and budesonide/formoterol (BUD/F) have been assessed against their respective monocomponents, but there is a need to compare these two therapies on a head-to-head basis.ObjectivesTo estimate the relative effects of fluticasone/salmeterol and budesonide/formoterol in terms of asthma control, safety and lung function.Search strategyWe searched the Cochrane Airways Group register of trials with prespecified terms. We performed additional hand searching of manufacturers' web sites and online trial registries. Searches are current to May 2008.Selection criteriaRandomised studies comparing fixed dose FP/SAL and BUD/ F were eligible, for a minimum of 12 weeks. Crossover studies were excluded. Our primary outcomes were: i) exacerbations requiring oral steroid bursts, ii) hospital admission and iii) serious adverse events.Data collection and analysisTwo authors independently assessed studies for inclusion in the review. We combined continuous data outcomes with a mean difference (MD), and dichotomous data outcomes with an odds ratio (OR).Main resultsFive studies met the review entry criteria (5537 participants). Primary outcomes: The odds of an exacerbation requiring oral steroids did not differ significantly between treatments (OR 0.89; 95% CI 0.73 to 1.09, three studies, 4515 participants). The odds of an exacerbation leading hospital admission were also not significantly different (OR 1.29; 95% CI 0.68 to 2.47, four studies, 4879 participants). The odds of serious adverse events did not differ significantly between treatments (OR 1.47; 95% CI 0.75, 2.86, three studies, 4054 participants). Secondary outcomes: Lung function outcomes, symptoms, rescue medication, exacerbations leading ED visit/hospital admission and adverse events were not significantly different between treatments.Authors' conclusionsThe evidence in this review indicates that differences in the requirement for oral steroids and hospital admission between BUD/F and FP/SAL do not reach statistical significance. However, the confidence intervals do not exclude clinically important differences between treatments in reducing exacerbations or causing adverse events. The width of the confidence intervals for the primary outcomes justify further trials in order to better determine the relative effects of these drug combinations. Although this review sought to assess the effects of these drugs in both adults and children, no trials were identified in the under-12s and research in this area is of a high priority
REFERQUAL: A pilot study of a new service quality assessment instrument in the GP Exercise Referral scheme setting
Background
The development of an instrument accurately assessing service quality in the GP Exercise Referral Scheme (ERS) industry could potentially inform scheme organisers of the factors that affect adherence rates leading to the implementation of strategic interventions aimed at reducing client drop-out.
Methods
A modified version of the SERVQUAL instrument was designed for use in the ERS setting and subsequently piloted amongst 27 ERS clients.
Results
Test re-test correlations were calculated via Pearson's 'r' or Spearman's 'rho', depending on whether the variables were Normally Distributed, to show a significant (mean r = 0.957, SD = 0.02, p < 0.05; mean rho = 0.934, SD = 0.03, p < 0.05) relationship between all items within the questionnaire. In addition, satisfactory internal consistency was demonstrated via Cronbach's 'α'. Furthermore, clients responded favourably towards the usability, wording and applicability of the instrument's items.
Conclusion
REFERQUAL is considered to represent promise as a suitable tool for future evaluation of service quality within the ERS community. Future research should further assess the validity and reliability of this instrument through the use of a confirmatory factor analysis to scrutinise the proposed dimensional structure
Early dyspnoea relief in acute heart failure: prevalence, association with mortality, and effect of rolofylline in the PROTECT Study
AIMS:
Dyspnoea and pulmonary and/or peripheral congestion are the most frequent manifestations of acute heart failure (AHF) and are important targets for therapy. We have assessed changes in dyspnoea, their relationship with mortality, and the effects of the adenosine A1 receptor antagonist rolofylline on these endpoints in patients enrolled in the PROTECT trial.
METHODS AND RESULTS:
PROTECT was a prospective, double-blind, placebo-controlled study assessing the effect of rolofylline in patients hospitalized for AHF with dyspnoea, fluid overload, increased plasma natriuretic peptides, and mild-to-moderate renal dysfunction. Early dyspnoea relief, prospectively defined as moderately or markedly better dyspnoea at both 24 and 48 h after the start of study drug administration, occurred in 49.8% of the patients. Early dyspnoea relief was associated with greater weight loss and with reduced mortality at Days 14 and 30 [hazard ratio (HR) 0.28, 95% confidence interval (CI): 0.15, 0.50; and 0.35, 95% CI: 0.22, 0.55, respectively]. Rolofylline administration was associated with an increase in the proportion of patients showing early dyspnoea relief (HR 1.30; 95% CI: 1.08, 1.57) and with a numerically lower mortality at 14 and 30 days, largely driven by the mortality due to HF [at 30 days, HR (95% CI, P-value): 0.65 (0.38-1.10, P= 0.107)]. Rolofylline did not reduce episodes of in-hospital worsening HF or post-discharge re-admissions, nor did it improve survival at 60 or 180 days.
CONCLUSION:
The present analysis from PROTECT demonstrated that more weight loss was associated with early dyspnoea relief and reduced short-term mortality
State based model of long-term potentiation and synaptic tagging and capture
Recent data indicate that plasticity protocols have not only synapse-specific but also more widespread effects. In particular, in synaptic tagging and capture (STC), tagged synapses can capture plasticity-related proteins, synthesized in response to strong stimulation of other synapses. This leads to long-lasting modification of only weakly stimulated synapses. Here we present a biophysical model of synaptic plasticity in the hippocampus that incorporates several key results from experiments on STC. The model specifies a set of physical states in which a synapse can exist, together with transition rates that are affected by high- and low-frequency stimulation protocols. In contrast to most standard plasticity models, the model exhibits both early- and late-phase LTP/D, de-potentiation, and STC. As such, it provides a useful starting point for further theoretical work on the role of STC in learning and memory
Status of the UCNτ experiment
The neutron is the simplest nuclear system that can be used to probe the structure of the weak interaction and search for physics beyond the standard model. Measurements of neutron lifetime and β-decay correlation coefficients with precisions of 0.02% and 0.1%, respectively, would allow for stringent constraints on new physics. The UCNτ experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime, τ_n = 877.7s (0.7s)_(stat) (+0.4/−0.2s)_(sys). We discuss the recent result from UCNτ, the status of ongoing data collection and analysis, and the path toward a 0.25 s measurement of the neutron lifetime with UCNτ
Identification of a novel zinc metalloprotease through a global analysis of clostridium difficile extracellular proteins
Clostridium difficile is a major cause of infectious diarrhea worldwide. Although the cell surface proteins are recognized to be important in clostridial pathogenesis, biological functions of only a few are known. Also, apart from the toxins, proteins exported by C. difficile into the extracellular milieu have been poorly studied. In order to identify novel extracellular factors of C. difficile, we analyzed bacterial culture supernatants prepared from clinical isolates, 630 and R20291, using liquid chromatography-tandem mass spectrometry. The majority of the proteins identified were non-canonical extracellular proteins. These could be largely classified into proteins associated to the cell wall (including CWPs and extracellular hydrolases), transporters and flagellar proteins. Seven unknown hypothetical proteins were also identified. One of these proteins, CD630_28300, shared sequence similarity with the anthrax lethal factor, a known zinc metallopeptidase. We demonstrated that CD630_28300 (named Zmp1) binds zinc and is able to cleave fibronectin and fibrinogen in vitro in a zinc-dependent manner. Using site-directed mutagenesis, we identified residues important in zinc binding and enzymatic activity. Furthermore, we demonstrated that Zmp1 destabilizes the fibronectin network produced by human fibroblasts. Thus, by analyzing the exoproteome of C. difficile, we identified a novel extracellular metalloprotease that may be important in key steps of clostridial pathogenesis
Factors influencing research engagement: research interest, confidence and experience in an Australian speech-language pathology workforce
Background: Recent initiatives within an Australia public healthcare service have seen a focus on increasing the research capacity of their workforce. One of the key initiatives involves encouraging clinicians to be research generators rather than solely research consumers. As a result, baseline data of current research capacity are essential to determine whether initiatives encouraging clinicians to undertake research have been effective. Speech pathologists have previously been shown to be interested in conducting research within their clinical role; therefore they are well positioned to benefit from such initiatives. The present study examined the current research interest, confidence and experience of speech language pathologists (SLPs) in a public healthcare workforce, as well as factors that predicted clinician research engagement
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