76,233 research outputs found

    Increased colonic propionate reduces anticipatory reward responses in the human striatum to high-energy foods

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    Background: Short-chain fatty acids (SCFAs), metabolites produced through the microbial fermentation of nondigestible dietary components, have key roles in energy homeostasis. Animal research suggests that colon-derived SCFAs modulate feeding behavior via central mechanisms. In humans, increased colonic production of the SCFA propionate acutely reduces energy intake. However, evidence of an effect of colonic propionate on the human brain or reward-based eating behavior is currently unavailable. Objectives: We investigated the effect of increased colonic propionate production on brain anticipatory reward responses during food picture evaluation. We hypothesized that elevated colonic propionate would reduce both reward responses and ad libitum energy intake via stimulation of anorexigenic gut hormone secretion. Design: In a randomized crossover design, 20 healthy nonobese men completed a functional magnetic resonance imaging (fMRI) food picture evaluation task after consumption of control inulin or inulin-propionate ester, a unique dietary compound that selectively augments colonic propionate production. The blood oxygen level–dependent (BOLD) signal was measured in a priori brain regions involved in reward processing, including the caudate, nucleus accumbens, amygdala, anterior insula, and orbitofrontal cortex (n = 18 had analyzable fMRI data). Results: Increasing colonic propionate production reduced BOLD signal during food picture evaluation in the caudate and nucleus accumbens. In the caudate, the reduction in BOLD signal was driven specifically by a lowering of the response to high-energy food. These central effects were partnered with a decrease in subjective appeal of high-energy food pictures and reduced energy intake during an ad libitum meal. These observations were not related to changes in blood peptide YY (PYY), glucagon-like peptide 1 (GLP-1), glucose, or insulin concentrations. Conclusion: Our results suggest that colonic propionate production may play an important role in attenuating reward-based eating behavior via striatal pathways, independent of changes in plasma PYY and GLP-1. This trial was registered at clinicaltrials.gov as NCT00750438

    The lung function profile of once-daily tiotropium and olodaterol via Respimat® is superior to that of twice-daily salmeterol and fluticasone propionate via Accuhaler® (ENERGITO® study)

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    Background: Tiotropium + olodaterol has demonstrated improvements beyond lung function benefits in a large Phase III clinical program as a once-daily maintenance treatment for COPD and may be a potential option for the initiation of maintenance treatment in COPD. Despite guideline recommendations that combined long-acting beta(2)-agonists and inhaled corticosteroids should only be used in individuals at high risk of exacerbation, there is substantial use in individuals at lower risk. This raises the question of the comparative effectiveness of this combination as maintenance treatment in this group compared to other combination regimens. Objective: The study aimed to assess the effect on lung function of once-daily tiotropium + olodaterol versus twice-daily salmeterol + fluticasone propionate in all participants with Global initiative for chronic Obstructive Lung Disease 2 or 3 (moderate to severe) COPD. Methods: This was a randomized, double-blind, double-dummy, four-treatment, complete crossover study in which participants received once-daily tiotropium + olodaterol (5/5 mu g and 2.5/5 mu g) via Respimat (R) and twice-daily salmeterol + fluticasone propionate (50/500 mu g and 50/250 mu g) via Accuhaler (R) for 6 weeks. The primary end point was change in forced expiratory volume in 1 second (FEV1) area under the curve from 0 hour to 12 hours (AUC(0-12)) relative to the baseline after 6 weeks. Results: Tiotropium + olodaterol 5/5 mu g and 2.5/5 mu g demonstrated statistically significant improvements in FEV1 AUC(0-12) compared to salmeterol + fluticasone propionate (improvements from baseline were 317 mL and 295 mL with tiotropium + olodaterol 5/5 mu g and 2.5/5 mu g, and 188 mL and 192 mL with salmeterol + fluticasone propionate 50/500 mu g and 50/250 mu g, respectively). Tiotropium + olodaterol was superior to salmeterol + fluticasone propionate in lung function secondary end points, including FEV1 area under the curve from 0 hour to 24 hours (AUC(0-24)). Conclusion: Once-daily tiotropium + olodaterol in participants with moderate-to-severe COPD provided superior lung function improvements to twice-daily salmeterol + fluticasone propionate. Dual bronchodilation can be considered to optimize lung function in individuals requiring maintenance treatment for COPD

    Safety and efficacy of fluticasone propionate in the topical treatment of skin diseases

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    Fluticasone propionate - the first carbothioate corticosteroid - has been classified as a potent anti-inflammatory drug for dermatological use. It is available as 0.05% cream and 0.005% ointment formulations for the acute and maintenance treatment of patients with dermatological disorders such as atopic dermatitis, psoriasis and vitiligo. This glucocorticoid is characterized by high lipophilicity, high glucocorticoid receptor binding and activation, and a rapid metabolic turnover in skin. Although skin blanching following fluticasone propionate exceeds that of corticosteroids of medium strength, several clinical trials demonstrate a low potential for cutaneous and systemic side-effects, even in difficult-to-treat areas like the face, the eyelids and intertriginous areas. Even among paediatric patients with atopic dermatitis, fluticasone propionate proved to be safe and effective. These pharmacological and clinical properties are reflected by the high therapeutic index of this glucocorticoid

    Defining Resonance Raman Spectral Responses to Substrate Binding by Cytochrome P450 from \u3cem\u3ePseudomonas putida\u3c/em\u3e

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    Resonance Raman spectra are reported for substrate-free and camphor-bound cytochrome P450cam and its isotopically labeled analogues that have been reconstituted with protoheme derivatives that bear -CD3 groups at the 1, 3, 5, and 8-positions (d12-protoheme) or deuterated methine carbons (d4-protoheme). In agreement with previous studies of this and similar enzymes, substrate binding induces changes in the high frequency and low frequency spectral regions, with the most dramatic effect in the low frequency region being activation of a new mode near 367 cm−1. This substrate-activated mode had been previously assigned as a second “propionate bending” mode (Chen et al., Biochemistry, 2004, 43, 1798–1808), arising in addition to the single propionate bending mode observed for the substrate-free form at 380 cm−1. In this work, this newly activated mode is observed to shift by 8 cm−1 to lower frequency in the d12-protoheme reconstituted enzyme (i.e., the same shift as that observed for the higher frequency “propionate bending” mode) and is therefore consistent with the suggested assignment. However, the newly acquired data for the d4-protoheme substituted analogue also support an earlier alternate suggestion (Deng et al., Biochemistry, 1999, 38, 13699–13706) that substrate binding activates several heme out-of-plane modes, one of which (γ6) is accidentally degenerate with the 367 cm−1 propionate bending mode. Finally, the study of the enzyme reconstituted with the protoheme-d4, which shifts the macrocycle ν10 mode, has now allowed a definitive identification of the vinyl CC stretching modes

    Relating Methanogen Community Structure and Anaerobic Digester Function

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    Much remains unknown about the relationships between microbial community structure and anaerobic digester function. However, knowledge of links between community structure and function, such as specific methanogenic activity (SMA) and COD removal rate, are valuable to improve anaerobic bioprocesses. In this work, quantitative structure–activity relationships (QSARs) were developed using multiple linear regression (MLR) to predict SMA using methanogen community structure descriptors for 49 cultures. Community descriptors were DGGE demeaned standardized band intensities for amplicons of a methanogen functional gene (mcrA). First, predictive accuracy of MLR QSARs was assessed using cross validation with training (n = 30) and test sets (n = 19) for glucose and propionate SMA data. MLR equations correlating band intensities and SMA demonstrated good predictability for glucose (q2 = 0.54) and propionate (q2 = 0.53). Subsequently, data from all 49 cultures were used to develop QSARs to predict SMA values. Higher intensities of two bands were correlated with higher SMA values; high abundance of methanogens associated with these two bands should be encouraged to attain high SMA values. QSARs are helpful tools to identify key microorganisms or to study and improve many bioprocesses. Development of new, more robust QSARs is encouraged for anaerobic digestion or other bioprocesses, including nitrification, nitritation, denitrification, anaerobic ammonium oxidation, and enhanced biological phosphorus removal

    Determination of the degree of substitution (DS) of mixed cellulose esters by elemental analysis

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    Equations for transforming the results of elemental analysis (EA) into degree of substitution (DS) values for aliphatic cellulose esters were developed. The equations allow to determine the DS of cellulose derivatives bearing not only one but also two different acyl substituents. Error transmission studies revealed that the accuracy of the DS-values for a pure sample depends on both the number of carbon atoms in the substituents and on the uncertainty of the EA, especially from the hydrogen content. This method provides accurate DS-values (± 0.10 in most cases) if H-content determinations are within ± 0.1

    Complete genome sequence of Syntrophobacter fumaroxidans strain (MPOB(T)).

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    Syntrophobacter fumaroxidans strain MPOB(T) is the best-studied species of the genus Syntrophobacter. The species is of interest because of its anaerobic syntrophic lifestyle, its involvement in the conversion of propionate to acetate, H2 and CO2 during the overall degradation of organic matter, and its release of products that serve as substrates for other microorganisms. The strain is able to ferment fumarate in pure culture to CO2 and succinate, and is also able to grow as a sulfate reducer with propionate as an electron donor. This is the first complete genome sequence of a member of the genus Syntrophobacter and a member genus in the family Syntrophobacteraceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 4,990,251 bp long genome with its 4,098 protein-coding and 81 RNA genes is a part of the Microbial Genome Program (MGP) and the Genomes to Life (GTL) Program project
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