336 research outputs found

    Montmorency cherry supplementation attenuates vascular dysfunction induced by prolonged forearm occlusion in overweight, middle-aged men

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    Flavonoid supplementation improves brachial artery flow-mediated dilation (FMD), but it is not known whether flavonoids protect against vascular dysfunction induced by ischemia-reperfusion (IR) injury and associated respiratory burst. In a randomized, double-blind, placebo-controlled, crossover study, we investigated whether 4 wk supplementation with freeze-dried Montmorency cherry (MC) attenuated suppression of FMD after IR induced by prolonged forearm occlusion. Twelve physically inactive overweight, middle-aged men (52.8 ± 5.8 yr, BMI: 28.1 ± 5.3 kg/m2) consumed MC (235 mg/day anthocyanins) or placebo capsules for 4 wk, with supplementation blocks separated by 4 wk washout. Before and after each supplementation block, FMD responses and plasma nitrate and nitrite ([ N O − 2 ]) concentrations were measured at baseline and 15, 30, and 45 min after prolonged (20 min) forearm occlusion. FMD response was significantly depressed by the prolonged occlusion ( P < 0.001). After a 45-min reperfusion, FMD was restored to baseline levels after MC (ΔFMD presupplementation: -30.5 ± 8.4%, postsupplementation: -0.6 ± 9.5%) but not placebo supplementation (ΔFMD presupplementation: -11.6 ± 10.6, postsupplementation: -25.4 ± 4.0%; condition × supplement interaction: P = 0.038). Plasma [ N O − 2 ] decreased after prolonged occlusion but recovered faster after MC compared with placebo (Δ45 min to baseline; MC: presupplementation: -15.3 ± 9.6, postsupplementation: -6.2 ± 8.1; Placebo: presupplementation: -16.3 ± 5.9, postsupplementation: -27.7 ± 11.1 nmol/l; condition × supplement × time interaction: P = 0.033). Plasma peroxiredoxin concentration ([Prx2]) was significantly higher after MC (presupplementation: 22.8 ± 1.4, postsupplementation: 28.0 ± 2.4 ng/ml, P = 0.029) but not after placebo supplementation (presupplementation: 22.1 ± 2.2, postsupplementation: 23.7 ± 1.5 ng/ml). In conclusion, 4 wk MC supplementation enhanced recovery of endothelium-dependent vasodilatation after IR, in parallel with faster recovery of plasma [ N O − 2 ], suggesting NO dependency. These protective effects seem to be related to increased plasma [Prx2], presumably conferring protection against the respiratory burst during reperfusion. NEW & NOTEWORTHY This is the first study to demonstrate that 4 wk of Montmorency cherry powder supplementation exerted protective effects on endothelium-dependent vasodilation after transient ischemia-reperfusion injury in overweight, physically inactive, nonmedicated, hypertensive middle-aged men. These effects seem to be due to increased nitric oxide availability, as evidenced by higher plasma nitrite concentration and peak arterial diameter during the flow-mediated dilation measurement. This may be a consequence of increased concentration of peroxiredoxin and other antioxidant systems and, hence, reduced reactive oxygen species exposure.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.This study was partially funded by a grant from the Cherry Research Committee, Aboo-Bakkar was supported by a Ph.D. studentship from the Universiti Kuala Lumpur, and Fulford’s salary was provided by National Institute for Health Research.accepted version (12 month embargo

    Benefícios do ômega 3 na prevenção de doença cardiovascular: Revisão integrativa de literatura

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    Introduction: Omega-3 polyunsaturated fatty acids such as alpha-linolenic acid (ALA), a fat found in plant foods, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both found in fish, have been considered relevant substances for the maintenance of health, so that supplementation is being considered relevant for the reduction of cardiovascular risks. Objective: To identify and analyze the scientific evidence available in the literature on the contribution of omega 3 in the prevention and treatment of cardiovascular disease. Materials and Methods: Integrative literature review, with deference to materials published in the Scielo and PubMed databases, which considered as inclusion criteria articles published in the last 5 years, available in full, in English, Spanish, and Portuguese, which addressed the proposed theme; the exclusion criteria were editorials, letters to the editor, review studies, theses, dissertations, and duplicate articles that did not correspond to the theme. Results: Based on the aforementioned scientific evidence, the body's omega-3 indices are relevant to identify possible cardiovascular risk, so it can therefore be used as an objective for treatment when there is a possible risk for these manifestations. This risk factor can be modified by taking EPA and DHA. The standard 1 g/day dose of EPA and DHA recommended by cardiac societies is, however, probably far from ideal for everyone, as not only this standard dose but also diet, individual genetic history, body mass index, calorie intake and disposal, and other factors all together probably determine a person's level of omega-3 fatty acids. Therefore, it is suggested that the omega-3 index acts not only as a risk factor for cardiovascular disease, but that other contexts allied to the patient's lifestyle should be considered. Conclusion: Diet or supplementation of these nutrients may result in cardiovascular and other types of benefits to society as a whole

    Fingerprinting the Substrate Specificity of M1 and M17 Aminopeptidases of Human Malaria, Plasmodium falciparum

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    Plasmodium falciparum, the causative agent of human malaria, expresses two aminopeptidases, PfM1AAP and PfM17LAP, critical to generating a free amino acid pool used by the intraerythrocytic stage of the parasite for proteins synthesis, growth and development. These exopeptidases are potential targets for the development of a new class of anti-malaria drugs.To define the substrate specificity of recombinant forms of these two malaria aminopeptidases we used a new library consisting of 61 fluorogenic substrates derived both from natural and unnatural amino acids. We obtained a detailed substrate fingerprint for recombinant forms of the enzymes revealing that PfM1AAP exhibits a very broad substrate tolerance, capable of efficiently hydrolyzing neutral and basic amino acids, while PfM17LAP has narrower substrate specificity and preferentially cleaves bulky, hydrophobic amino acids. The substrate library was also exploited to profile the activity of the native aminopeptidases in soluble cell lysates of P. falciparum malaria.This data showed that PfM1AAP and PfM17LAP are responsible for majority of the aminopeptidase activity in these extracts. These studies provide specific substrate and mechanistic information important for understanding the function of these aminopeptidases and could be exploited in the design of new inhibitors to specifically target these for anti-malaria treatment

    Two-pronged attack: dual inhibition of Plasmodium falciparum M1 and M17 metalloaminopeptidases by a novel series of hydroxamic acid-based inhibitors

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    Plasmodium parasites, the causative agents of malaria, have developed resistance to most of our current antimalarial therapies, including artemisinin combination therapies which are widely described as our last line of defense. Antimalarial agents with a novel mode of action are urgently required. Two Plasmodium falciparum aminopeptidases, PfA-M1 and PfA-M17, play crucial roles in the erythrocytic stage of infection and have been validated as potential antimalarial targets. Using compound-bound crystal structures of both enzymes, we have used a structure-guided approach to develop a novel series of inhibitors capable of potent inhibition of both PfA-M1 and PfA-M17 activity and parasite growth in culture. Herein we describe the design, synthesis, and evaluation of a series of hydroxamic acid-based inhibitors and demonstrate the compounds to be exciting new leads for the development of novel antimalarial therapeutics

    Omega-3 polyunsaturated fatty acid supplementation versus placebo on vascular health, glycaemic control, and metabolic parameters in people with type 1 diabetes: a randomised controlled preliminary trial

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    Background: The role of omega-3 polyunsaturated fatty acids (n-3PUFA), and the potential impact of n-3PUFA supplementation, in the treatment and management of type 1 diabetes (T1D) remains unclear and controversial. Therefore, this study aimed to examine the efficacy of daily high-dose-bolus n-3PUFA supplementation on vascular health, glycaemic control, and metabolic parameters in subjects with T1D. Methods: Twenty-seven adults with T1D were recruited to a 6-month randomised, double-blind, placebo-controlled trial. Subjects received either 3.3 g/day of encapsulated n-3PUFA or encapsulated 3.0 g/day corn oil placebo (PLA) for 6-months, with follow-up at 9-months after 3-month washout. Erythrocyte fatty acid composition was determined via gas chromatography. Endpoints included inflammation-associated endothelial biomarkers (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], E-selectin, P-selectin, pentraxin-3, vascular endothelial growth factor [VEGF]), and their mediator tumor necrosis factor alpha [TNFα] analysed via immunoassay, vascular structure (carotid intima-media thickness [CIMT]) and function (brachial artery flow mediated dilation [FMD]) determined via ultrasound technique, blood pressure, glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), and postprandial metabolism. Results: Twenty subjects completed the trial in full. In the n-3PUFA group, the mean ± SD baseline n-3PUFA index of 4.93 ± 0.94% increased to 7.67 ± 1.86% (P  0.05). Conclusions: This study indicates that daily high-dose-bolus of n-3PUFA supplementation for 6-months does not improve vascular health, glucose homeostasis, or metabolic parameters in subjects with T1D. The findings from this preliminary RCT do not support the use of therapeutic n-3PUFA supplementation in the treatment and management of T1D and its associated complications. Trial Registration ISRCTN, ISRCTN40811115. Registered 27 June 2017, http://www.isrctn.com/ISRCTN40811115

    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH &lt; 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 &lt; κλ &lt; 6.9 and −0.5 &lt; κ2V &lt; 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Comparison of inclusive and photon-tagged jet suppression in 5.02 TeV Pb+Pb collisions with ATLAS

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    Measurement of the H → γ γ and H → ZZ∗ → 4 cross-sections in pp collisions at √s = 13.6 TeV with the ATLAS detector

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    The inclusive Higgs boson production cross section is measured in the di-photon and the Z Z∗ → 4 decay channels using 31.4 and 29.0 fb−1 of pp collision data respectively, collected with the ATLAS detector at a centre of-mass energy of √s = 13.6 TeV. To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the chan nel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are σfid,γ γ = 76+14 −13 fb, and σfid,4 = 2.80 ± 0.74 fb, in agreement with the corresponding Standard Model predic tions of 67.6±3.7 fb and 3.67±0.19 fb. Assuming Standard Model acceptances and branching fractions for the two chan nels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of σ (pp → H) = 67+12 −11 pb and 46±12 pb at 13.6 TeV from the di-photon and Z Z∗ → 4 measurements respectively. The two measure ments are combined into a total cross-section measurement of σ (pp → H) = 58.2±8.7 pb, to be compared with the Stan dard Model prediction of σ (pp → H)SM = 59.9 ± 2.6 p

    Search for pairs of muons with small displacements in pp collisions at root s=13 TeV with the ATLAS detector

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    A search for new phenomena giving rise to pairs of opposite electrically charged muons with impact parameters in the millimeter range is presented, using 139 fb−1 of √s = 13 TeV pp collision data from the ATLAS detector at the LHC. The search targets the gap in coverage between existing searches targeting final states with leptons with large displacement and prompt leptons. No significant excess over the background expectation is observed and exclusion limits are set on the mass of long-lived scalar supersymmetric muon-partners (smuons) with much lower lifetimes than previously targeted by displaced muon searches. Smuon lifetimes down to 1 ps are excluded for a smuon mass of 100 GeV, and smuon masses up to 520 GeV are excluded for a proper lifetime of 10 ps, at 95% confidence level. Finally, model-independent limits are set on the contribution from new phenomena to the signal-region yield
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