565 research outputs found

    Effects of Acute Tryptophan Depletion on Brain Serotonin Function and Concentrations of Dopamine and Norepinephrine in C57BL/6J and BALB/cJ Mice

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    Acute tryptophan depletion (ATD) is a method of lowering brain serotonin (5-HT). Administration of large neutral amino acids (LNAA) limits the transport of endogenous tryptophan (TRP) across the blood brain barrier by competition with other LNAAs and subsequently decreases serotonergic neurotransmission. A recent discussion on the specificity and efficacy of the ATD paradigm for inhibition of central nervous 5-HT has arisen. Moreover, side effects such as vomiting and nausea after intake of amino acids (AA) still limit its use. ATD Moja-De is a revised mixture of AAs which is less nauseating than conventional protocols. It has been used in preliminary clinical studies but its effects on central 5-HT mechanisms and other neurotransmitter systems have not been validated in an animal model. We tested ATD Moja-De (TRP−) in two strains of mice: C57BL/6J, and BALB/cJ, which are reported to have impaired 5-HT synthesis and a more anxious phenotype relative to other strains of mice. ATD Moja-De lowered brain TRP, significantly decreased 5-HT synthesis as indexed by 5-HTP levels after decarboxlyase inhibition, and lowered 5-HT and 5-HIAA in both strains of mice, however more so in C57BL/6J than in BALB/cJ. Dopamine and its metabolites as well as norepinephrine were not affected. A balanced (TRP+) control mixture did not raise 5-HT or 5-HIAA. The present findings suggest that ATD Moja-De effectively and specifically suppresses central serotonergic function. These results also demonstrate a strain- specific effect of ATD Moja-De on anxiety-like behavior

    Improvement of primary care for patients with chronic heart failure: A study protocol for a cluster randomised trial comparing two strategies

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    <p>Abstract</p> <p>Background</p> <p>Many patients with chronic heart failure (CHF), a common condition with high morbidity and mortality rates, receive treatment in primary care. To improve the management of CHF in primary care, we developed an implementation programme comprised of educational and organisational components, with support by a practice visitor and focus both on drug treatment and lifestyle advice, and on organisation of care within the practice and collaboration with other healthcare providers. Tailoring has been shown to improve the success of implementation programmes, but little is known about what would be best methods for tailoring, specifically with respect to CHF in primary care.</p> <p>Methods/design</p> <p>We describe the study protocol of a cluster randomised controlled trial to examine the effectiveness of tailoring a CHF implementation programme to general practices compared to a standardised way of delivering a programme. The study population will consist of 60 general practitioners (GPs) and the CHF patients they include. GPs are randomised in blocks of four, stratified according to practice size. With a tailored implementation programme GPs prioritise the issues that will form the bases of the support for the practice visits. These may comprise several issues, both educational and organizational.</p> <p>The primary outcome measures are patient's experience of receiving structured primary care for CHF (PACIC, a questionnaire related to the Chronic Care Model), patients' health-related utilities (EQ-5D), and drugs prescriptions using the guideline adherence index. Patients being clustered in practices, multilevel regression analyses will be used to explore the effect of practice size and type of intervention programme. In addition we will examine both changes within groups and differences at follow-up between groups with respect to drug dosages and advice on lifestyle issues. Furthermore, in interviews the feasibility of the programme and goal attainment, organisational changes in CHF care, and formalised cooperation with other disciplines will be assessed.</p> <p>Discussion</p> <p>In the tailoring of the programme we will present the GPs a list with barriers; GPs will assess relevance and possibility to solve these barriers. The list is rigorously developed and tested in various projects. The factors for ordering the barriers are related to the innovation, the healthcare professional, the patient, and the context.</p> <p>CHF patients do not form a homogeneous group. Subgroup analyses will be performed based on the distinction between systolic CHF and CHF with preserved left ventricular function (diastolic CHF).</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN18812755">ISRCTN18812755</a></p

    Immunological imbalance between IFN-Âł and IL-10 levels in the sera of patients with the cardiac form of Chagas disease

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    The immune response is crucial for protection against disease; however, immunological imbalances can lead to heart and digestive tract lesions in chagasic patients. Several studies have evaluated the cellular and humoral immune responses in chagasic patients in an attempt to correlate immunological findings with clinical forms of Chagas disease. Moreover, immunoglobulins and cytokines are important for parasitic control and are involved in lesion genesis. Here, cytokine and IgG isotype production were studied, using total epimastigote antigen on sera of chagasic patients with indeterminate (IND, n = 27) and cardiac (CARD, n = 16) forms of the disease. Samples from normal, uninfected individuals (NI, n = 30) were use as controls. The results showed that sera from both IND and CARD patients contained higher levels of Trypanosoma cruzi-specific IgG1 (IgG1) antibodies than sera from NI. No difference in IgG2 production levels was observed between NI, IND and CARD patients, nor was a difference in IL-10 and IFN-Âł production detected in the sera of IND, CARD and NI patients. However, IND patients displayed a positive correlation between IL-10 and IFN-Âł levels in serum, while CARD patients showed no such correlation, indicating an uncontrolled inflammatory response in CARD patients. These findings support the hypothesis that a lack of efficient regulation between IFN-Âł and IL-10 productions in CARD patients may lead to cardiac immunopathology.CNP

    Characterization of MgtC, a Virulence Factor of Salmonella enterica Serovar Typhi

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    The MgtC is a virulence factor in Salmonella Typhimurium that is required for growth at low-Mg2+ concentrations and intramacrophage survival. This gene is codified in a conserved region of the Salmonella pathogenicity island 3 (SPI-3), and is also present in the chromosome of other Salmonella serovars. In this study we characterized the MgtC factor in S. Typhi, a human specific pathogen, by using mgtC and SPI-3 mutant strains. We found that MgtC is the most important factor codified in the SPI-3 of S. Typhi for growth in low-Mg2+ media and survival within human cells. In addition, by using reporter genes we determined that the low-Mg2+ concentration, acidic media and PhoP regulator induce mgtC expression in S. Typhi. We suggest that MgtC is the most important virulence factor codified in the SPI-3 of S. Typhi

    A review of elliptical and disc galaxy structure, and modern scaling laws

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    A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

    Search for rare quark-annihilation decays, B --> Ds(*) Phi

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    We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

    Early detection and counselling intervention of asthma symptoms in preschool children: study design of a cluster randomised controlled trial

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    Background. Prevention of childhood asthma is an important public health objective. This study evaluates the effectiveness of early detection of preschool children with asthma symptoms, followed by a counselling intervention at preventive child health centres. Early detection and counselling is expected to reduce the prevalence of asthma symptoms and improve health-related quality of life at age 6 years. Methods/design. This cluster randomised controlled trial was embedded within the Rotterdam population-based prospective cohort study Generation R in which 7893 children (born between April 2002 and January 2006) participated in the postnatal phase. Sixteen child health centres are involved, randomised into 8 intervention and 8 control centres. Since June 2005, an early detection tool has been applied at age 14, 24, 36 and 45 months at the intervention centres. Children who met the intervention criteria received counselling intervention (personal advice to parents to prevent smoke exposure of the child, and/or referral to the general practitioner or asthma nurse). The primary outcome was asthma diagnosis at age 6 years. Secondary outcomes included frequency and severity of asthma symptoms, health-related quality of life, fractional exhaled nitric oxide and airway resistance at age 6 years. Analysis was according to the intention-to-treat principle. Data collection will be completed end 2011. Discussion. This study among preschool children provides insight into the effectiveness of early detection of asthma symptoms followed by a counselling intervention at preventive child health centres. Trial registration. Current Controlled Trials ISRCTN15790308
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