Activity of arginine-phenylalanine and arginine-tryptophan-based surfactants against Staphylococcus aureus

Aims: This study aimed to evaluate the antibacterial effect of two new cationic surfactants based on phenylalanine-arginine (LPAM) and tryptophan-arginine (LTAM). Materials & methods: Antibacterial activity, mechanism of action and interactions with Staphylococcus aureus enzymes were measured through microbiological, flow cytometry and molecular docking assays, respectively. Results & conclusion: These compounds showed antibacterial activity in the range of 4.06-16.24 μg/ml against planktonic cells and no activity against mature biofilms, since they caused a loss of membrane integrity and increased DNA damage, as revealed by flow cytometry analysis. In silico assays revealed the existence of molecular bonds such as hydrogen bonds, mainly with DNA. Therefore, these compounds have promising pharmacological activity against MRSA strains.The authors would like to thank Central Analítica-UFC/CT-INFRA/MCTI- SISANO/Pró-Equipamentos CAPES for the support.Peer reviewe

Inflammatory responses to acute exercise during pulmonary rehabilitation in patients with COPD

Objective Pulmonary rehabilitation is a cornerstone treatment in the management of chronic obstructive pulmonary disease (COPD). Acute bouts of exercise can lead to short bursts of inflammation in healthy individuals. However, it is unclear how COPD patients respond to acute bouts of exercise. This study assessed inflammatory responses to exercise in COPD patients at the start (phase 1) and end (phase 2) of pulmonary rehabilitation. Methods Blood samples were collected before and after an acute exercise bout at the start (phase 1, n = 40) and end (phase 2, n = 27) of pulmonary rehabilitation. The primary outcome was change in fibrinogen concentrations. Secondary outcomes were changes in CRP concentrations, total/differential leukocyte counts, markers of neutrophil activation (CD11b, CD62L and CD66b), and neutrophil subsets (mature, suppressive, immature, progenitor). Results Acute exercise (phase 1) did not induce significant changes in fibrinogen (p = 0.242) or CRP (p = 0.476). Total leukocyte count [mean difference (MD), 0.5 ± 1.1 (109 L−1); p = 0.004], neutrophil count [MD, 0.4 ± 0.8 (109 L−1); p < 0.001], and immature neutrophils (MD, 0.6 ± 0.8%; p < 0.001) increased post-exercise. Neutrophil activation markers, CD11b (p = 0.470), CD66b (p = 0.334), and CD62L (p = 0.352) were not significantly altered post-exercise. In comparison to the start of pulmonary rehabilitation (phase 2), acute exercise at the end of pulmonary rehabilitation led to a greater fibrinogen response (MD, 84 mg/dL (95% CI − 14, 182); p = 0.045). Conclusion An acute bout of exercise does not appear to induce significant alterations in the concentrations of inflammatory mediators but can increase white blood cell subsets post-exercise. A greater fibrinogen response to acute exercise is seen at the end of pulmonary rehabilitation when compared to the start. Further research is required to understand the clinical context of these acute inflammatory responses to exercise

Effects of 12 weeks of aerobic training on autonomic modulation, mucociliary clearance, and aerobic parameters in patients with COPD

Marceli Rocha Leite,1 Ercy Mara Cipulo Ramos,1 Carlos Augusto Kalva-Filho,2 Ana Paula Coelho Figueira Freire,1 Bruna Spolador de Alencar Silva,1 Juliana Nicolino,1 Alessandra Choqueta de Toledo-Arruda,3 Marcelo Papoti,4 Luiz Carlos Marques Vanderlei,1 Dionei Ramos1 1Department of Physiotherapy, S&atilde;o Paulo State University, Presidente Prudente, 2Program in Rehabilitation and Functional Performance, S&atilde;o Paulo University, Ribeir&atilde;o Preto, 3Department of Medicine, S&atilde;o Paulo University, 4School of Physical Education and Sport of Ribeir&atilde;o Preto, S&atilde;o Paulo University, Ribeir&atilde;o Preto, S&atilde;o Paulo, Brazil Introduction: Patients with chronic obstructive pulmonary disease (COPD) exhibit aerobic function, autonomic nervous system, and mucociliary clearance alterations. These parameters can be attenuated by aerobic training, which can be applied with continuous or interval efforts. However, the possible effects of aerobic training, using progressively both continuous and interval sessions (ie, linear periodization), require further investigation.Aim: To analyze the effects of 12-week aerobic training using continuous and interval sessions on autonomic modulation, mucociliary clearance, and aerobic function in patients with COPD.Methods: Sixteen patients with COPD were divided into an aerobic (continuous and interval) training group (AT) (n=10) and a control group (CG) (n=6). An incremental test (initial speed of 2.0 km&middot;h-1, constant slope of 3%, and increments of 0.5 km&middot;h-1 every 2 minutes) was performed. The training group underwent training for 4 weeks at 60% of the peak velocity reached in the incremental test (vVO2peak) (50 minutes of continuous effort), followed by 4 weeks of sessions at 75% of vVO2peak (30 minutes of continuous effort), and 4 weeks of interval training (5&times;3-minute effort at vVO2peak, separated by 1 minute of passive recovery). Intensities were adjusted through an incremental test performed at the end of each period.Results: The AT presented an increase in the high frequency index (ms2) (P=0.04), peak oxygen uptake (VO2peak) (P=0.01), vVO2peak (P=0.04), and anaerobic threshold (P=0.02). No significant changes were observed in the CG (P&gt;0.21) group. Neither of the groups presented changes in mucociliary clearance after 12 weeks (AT: P=0.94 and CG: P=0.69).Conclusion: Twelve weeks of aerobic training (continuous and interval sessions) positively influenced the autonomic modulation and aerobic parameters in patients with COPD. However, mucociliary clearance was not affected by aerobic training. Keywords: COPD, exercise, aerobic treatment, mucociliary clearanc

Measurement of the relative width difference of the B0B^0-Bˉ0\bar B^0 system with the ATLAS detector

20 pages plus author list + cover page (38 pages total), 5 figures, 2 tables, submitted to Journal of High Energy Physics, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2015-01/ - See paper for full list of authorsInternational audienceThis paper presents the measurement of the relative width difference $\Delta \Gamma_d / \Gamma_d$ of the $B^0$-$\bar B^0$ system using the data collected by the ATLAS experiment at the LHC in $p p$ collisions at $\sqrt{s} = 7$ TeV and $\sqrt{s} = 8$ TeV and corresponding to an integrated luminosity of 25.2 fb$^{-1}$. The value of $\Delta \Gamma_d / \Gamma_d$ is obtained by comparing the decay-time distributions of $B^0 \to J/\psi K_S$ and $B^0 \to J/\psi K^{*0}(892)$ decays. The result is \Delta \Gamma_d / \Gamma_d = (-0.1 \pm 1.1~\mbox{(stat.)} \pm 0.9~\mbox{(syst.)}) \times 10^{-2}. Currently, this is the most precise single measurement of $\Delta \Gamma_d / \Gamma_d$. It agrees with the Standard Model prediction and the measurements by other experiments