421 research outputs found

    The parts are greater than the sum of the whole. Exploring the Process of Change in a Pain Management Programme using Single Case Study Design

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    This three-part thesis reviews the effectiveness of psychological interventions for chronic non-cancer pain on healthcare use and sick leave from work, and explores the process of change in a pain management programme using single case methods. Part 1 is a meta-analysis of 16 randomised controlled trials of psychological interventions in a chronic pain population. Small to moderate effect sizes were found for reduced healthcare use but no significant benefit for sick leave. Part 2 is a study using single case design methodology to explore trajectories of change in 8 patients attending a CBT-based chronic pain management programme. Baseline, intervention and bi-weekly follow-up self-report of catastrophic thinking, mood, self-efficacy, and goal attainment, and of process variables of working alliance and adherence, were supplemented by a post treatment change telephone interview which was qualitatively analysed. Detailed examination of change for each participant provided rich data: three participants improved significantly over the course of the programme, three deteriorated, and all improved in at least one goal. Therapeutic alliance was high and participants rated central elements of the programme, explanations of their pain, and peer support/group membership as important. Part 3 is a critical appraisal of the study and the review, contrasting the approaches, and concluding with a personal reflection on the process

    Birth data accessibility via primary care health records to classify health status in a multi-ethnic population of children: an observational study

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    This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/license/by/4.0

    Pathogenesis of aerosolized Eastern Equine Encephalitis virus infection in guinea pigs

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    Mice and guinea pigs were experimentally exposed to aerosols containing regionally-distinct strains (NJ1959 or ArgM) of eastern equine encephalitis virus (EEEV) at two exclusive particle size distributions. Mice were more susceptible to either strain of aerosolized EEEV than were guinea pigs; however, clinical signs indicating encephalitis were more readily observed in the guinea pigs. Lower lethality was observed in both species when EEEV was presented at the larger aerosol distribution (> 6 μm), although the differences in the median lethal dose (LD50) were not significant. Virus isolation and immunohistochemistry indicated that virus invaded the brains of guinea pigs within one day postexposure, regardless of viral strain or particle size distribution. Immunohistochemistry further demonstrated that neuroinvasion occurred through the olfactory system, followed by transneuronal spread to all regions of the brain. Olfactory bipolar neurons and neurons throughout the brain were the key viral targets. The main microscopic lesions in infected guinea pigs were neuronal necrosis, inflammation of the meninges and neuropil of the brain, and vasculitis in the brain. These results indicate that guinea pigs experimentally infected by aerosolized EEEV recapitulate several key features of fatal human infection and thus should serve as a suitable animal model for aerosol exposure to EEEV

    Antibiotic treatment leads to the elimination of Wolbachia endosymbionts and sterility in the diplodiploid collembolan Folsomia candida

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    <p>Abstract</p> <p>Background</p> <p><it>Wolbachia </it>is an extremely widespread bacterial endosymbiont of arthropods and nematodes that causes a variety of reproductive peculiarities. Parthenogenesis is one such peculiarity but it has been hypothesised that this phenomenon may be functionally restricted to organisms that employ haplodiploid sex determination. Using two antibiotics, tetracycline and rifampicin, we attempted to eliminate <it>Wolbachia </it>from the diplodiploid host <it>Folsomia candida</it>, a species of springtail which is a widely used study organism.</p> <p>Results</p> <p>Molecular assays confirmed that elimination of <it>Wolbachia </it>was successfully achieved through continuous exposure of populations (over two generations and several weeks) to rifampicin administered as 2.7% dry weight of their yeast food source. The consequence of this elimination was total sterility of all individuals, despite the continuation of normal egg production.</p> <p>Conclusion</p> <p>Microbial endosymbionts play an obligatory role in the reproduction of their diplodiploid host, most likely one in which the parthenogenetic process is facilitated by <it>Wolbachia</it>. A hitherto unknown level of host-parasite interdependence is thus recorded.</p

    First order reversal curves and intrinsic parameter determination for magnetic materials; Limitations of hysteron-based approaches in correlated systems

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    The generic problem of extracting information on intrinsic particle properties from the whole class of interacting magnetic fine particle systems is a long standing and difficult inverse problem. As an example, the Switching Field Distribution (SFD) is an important quantity in the characterization of magnetic systems, and its determination in many technological applications, such as recording media, is especially challenging. Techniques such as the first order reversal curve (FORC) methods, were developed to extract the SFD from macroscopic measurements. However, all methods rely on separating the contributions to the measurements of the intrinsic SFD and the extrinsic effects of magnetostatic and exchange interactions. We investigate the underlying physics of the FORC method by applying it to the output predictions of a kinetic Monte-Carlo model with known input parameters. We show that the FORC method is valid only in cases of weak spatial correlation of the magnetisation and suggest a more general approach

    Docosahexaenoic and eicosapentaenoic acids increase prion formation in neuronal cells

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    <p>Abstract</p> <p>Background</p> <p>The transmissible spongiform encephalopathies, otherwise known as prion diseases, occur following the conversion of the cellular prion protein (PrP<sup>C</sup>) to an alternatively folded, disease-associated isoform (PrP<sup>Sc</sup>). Recent studies suggest that this conversion occurs via a cholesterol-sensitive process, as cholesterol synthesis inhibitors reduced the formation of PrP<sup>Sc </sup>and delayed the clinical phase of scrapie infection. Since polyunsaturated fatty acids also reduced cellular cholesterol levels we tested their effects on PrP<sup>Sc </sup>formation in three prion-infected neuronal cell lines (ScGT1, ScN2a and SMB cells).</p> <p>Results</p> <p>We report that treatment with docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) or the cholesterol synthesis inhibitor simvastatin reduced the amounts of free cholesterol in membrane extracts from prion-infected neuronal cells. Simvastatin reduced cholesterol production while DHA and EPA promoted the conversion of free cholesterol to cholesterol esters. Crucially, while simvastatin reduced PrP<sup>Sc </sup>formation, both DHA and EPA significantly increased the amounts of PrP<sup>Sc </sup>in these cells. Unlike simvastatin, the effects of DHA and EPA on PrP<sup>Sc </sup>content were not reversed by stimulation of cholesterol synthesis with mevalonate. Treatment of ScGT1 cells with DHA and EPA also increased activation of cytoplasmic phospholipase A<sub>2 </sub>and prostaglandin E<sub>2 </sub>production. Finally, treatment of neuronal cells with DHA and EPA increased the amounts of PrP<sup>C </sup>expressed at the cell surface and significantly increased the half-life of biotinylated PrP<sup>C</sup>.</p> <p>Conclusion</p> <p>We report that although treatment with DHA or EPA significantly reduced the free cholesterol content of prion-infected cells they significantly increased PrP<sup>Sc </sup>formation in three neuronal cell lines. DHA or EPA treatment of infected cells increased activation of phospholipase A<sub>2</sub>, a key enzyme in PrP<sup>Sc </sup>formation, and altered the trafficking of PrP<sup>C</sup>. PrP<sup>C </sup>expression at the cell surface, a putative site for the PrP<sup>Sc </sup>formation, was significantly increased, and the rate at which PrP<sup>C </sup>was degraded was reduced. Cholesterol depletion is seen as a potential therapeutic strategy for prion diseases. However, these results indicate that a greater understanding of the precise relationship between membrane cholesterol distribution, PrP<sup>C </sup>trafficking, cell activation and PrP<sup>Sc </sup>formation is required before cholesterol manipulation can be considered as a prion therapeutic.</p

    Determinants of access to experimental antiretroviral drugs in an Italian cohort of patients with HIV: a multilevel analysis

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    <p>Abstract</p> <p>Background</p> <p>Identification of the determinants of access to investigational drugs is important to promote equity and scientific validity in clinical research. We aimed to analyze factors associated with the use of experimental antiretrovirals in Italy.</p> <p>Methods</p> <p>We studied participants in the Italian Cohort of Antiretroviral-Naive Patients (ICoNA). All patients 18 years or older who had started cART (≥ 3 drugs including at least two NRTI) after their enrolment and during 1997-2007 were included in this analysis. We performed a random effect logistic regression analysis to take into account clustering observations within clinical units. The outcome variable was the use of an experimental antiretroviral, defined as an antiretroviral started before commercial availability, in any episode of therapy initiation/change. Use of an experimental antiretroviral obtained through a clinical trial or an expanded access program (EAP) was also analyzed separately.</p> <p>Results</p> <p>A total of 9,441 episodes of therapy initiation/change were analyzed in 3,752 patients. 392 episodes (360 patients) involved an experimental antiretroviral. In multivariable analysis, factors associated with the overall use of experimental antiretrovirals were: number of experienced drugs (≥ 8 drugs versus "naive": adjusted odds ratio [AOR] = 3.71) or failed antiretrovirals(3-4 drugs and ≥ 5 drugs versus 0-2 drugs: AOR = 1.42 and 2.38 respectively); calendar year (AOR = 0.80 per year) and plasma HIV-RNA copies/ml at therapy change (≥ 4 log versus < 2 log: AOR = 1.55). The probability of taking an experimental antiretroviral through a trial was significantly lower for patients suffering from liver co-morbidity(AOR = 0.65) and for those who experienced 3-4 drugs (vs naive) (AOR = 0.55), while it increased for multi-treated patients(AOR = 2.60). The probability to start an experimental antiretroviral trough an EAP progressively increased with the increasing number of experienced and of failed drugs and also increased for patients with liver co-morbidity (AOR = 1.44; p = 0.053). and for male homosexuals (vs heterosexuals: AOR = 1.67). Variability of the random effect associated to clinical units was statistically significant (p < 0.001) although no association was found with specific characteristics of clinical unit examined.</p> <p>Conclusions</p> <p>Among patients with HIV infection in Italy, access to experimental antiretrovirals seems to be influenced mainly by exhaustion of treatment options and not by socio-demographic factors.</p

    Human Glycolipid Transfer Protein (GLTP) Expression Modulates Cell Shape

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    Glycolipid transfer protein (GLTP) accelerates glycosphingolipid (GSL) intermembrane transfer via a unique lipid transfer/binding fold (GLTP-fold) that defines the GLTP superfamily and is the prototype for GLTP-like domains in larger proteins, i.e. phosphoinositol 4-phosphate adaptor protein-2 (FAPP2). Although GLTP-folds are known to play roles in the nonvesicular intracellular trafficking of glycolipids, their ability to alter cell phenotype remains unexplored. In the present study, overexpression of human glycolipid transfer protein (GLTP) was found to dramatically alter cell phenotype, with cells becoming round between 24 and 48 h after transfection. By 48 h post transfection, ∼70% conversion to the markedly round shape was evident in HeLa and HEK-293 cells, but not in A549 cells. In contrast, overexpression of W96A-GLTP, a liganding-site point mutant with abrogated ability to transfer glycolipid, did not alter cell shape. The round adherent cells exhibited diminished motility in wound healing assays and an inability to endocytose cholera toxin but remained viable and showed little increase in apoptosis as assessed by poly(ADP-ribose) polymerase cleavage. A round cell phenotype also was induced by overexpression of FAPP2, which binds/transfers glycolipid via its C-terminal GLTP-like fold, but not by a plant GLTP ortholog (ACD11), which is incapable of glycolipid binding/transfer. Screening for human protein partners of GLTP by yeast two hybrid screening and by immuno-pulldown analyses revealed regulation of the GLTP-induced cell rounding response by interaction with δ-catenin. Remarkably, while δ-catenin overexpression alone induced dendritic outgrowths, coexpression of GLTP along with δ-catenin accelerated transition to the rounded phenotype. The findings represent the first known phenotypic changes triggered by GLTP overexpression and regulated by direct interaction with a p120-catenin protein family member
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