Training Effects on ROS Production Determined by Electron Paramagnetic Resonance in Master Swimmers

Acute exercise induces an increase in Reactive Oxygen Species (ROS) production dependent on exercise intensity with highest ROS amount generated by strenuous exercise. However, chronic repetition of exercise, that is, exercise training, may reduce exercise-induced oxidative stress. Aim of this study was to evaluate the effects of 6-weeks high-intensity discontinuous training (HIDT), characterized by repeated variations of intensity and changes of redox potential, on ROS production and antioxidant capacity in sixteen master swimmers. Time course changes of ROS generation were assessed by Electron Paramagnetic Resonance in capillary blood by a microinvasive approach. An incremental arm-ergometer exercise (IE) until exhaustion was carried out at both before (PRE) and after (POST) training (Trg) period. A significant (P<0.01) increase of ROS production from REST to the END of IE in PRE Trg (2.82±0.66 versus 3.28±0.66 µmol·min−1) was observed. HIDT increased peak oxygen consumption (36.1±4.3 versus 40.6±5.7 mL·kg−1·min−1 PRE and POST Trg, resp.) and the antioxidant capacity (+13%) while it significantly decreased the ROS production both at REST (−20%) and after IE (−25%). The observed link between ROS production, adaptive antioxidant defense mechanisms, and peak oxygen consumption provides new insight into the correlation between ROS response pathways and muscle metabolic function

Inkjet Printed Nanohydrogel Coated Carbon Nanotubes Electrodes For Matrix Independent Sensing

Polyacrylamide (PA) based hydrogels are used in several applications including polyacrylamide gel electrophoresis and sensing devices. Homogeneous and compact PA films can be prepared based on chemical or photopolymerization processes. However, the accurate and reproducible coating of substrates with nanohydrogel patterns is challenging due to the in situ polymerization and deposition requirements. Herein, we report an inkjet printing (IJP) concept with simultaneously performed UV photopolymerization of a specifically prepared acrylamide/N,N′-methylenebis(acrylamide) containing ink. A prepolymerization step of the hydrogel precursor molecules was implemented in the ink formulation protocol to adjust the viscosity of the ink and to enhance the rate of polymerization during printing. After the optimization of the printing parameters, a nanometer thin PA hydrogel coating with well distributed nanopores was achieved on top of a stand-alone carbon nanotubes (CNTs) pattern. Batches of fully inkjet printed PA/CNT modified electrodes were prepared that showed outstanding improvements for the electrochemical detection of antioxidants in complex matrices such as untreated orange juice and red wine samples thanks to the properties of the PA coating

Biomarkers of oxidative stress and its association with the urinary reducing capacity in bus maintenance workers

<p>Abstract</p> <p>Background</p> <p>Exposure to particles (PM) induces adverse health effects (cancer, cardiovascular and pulmonary diseases). A key-role in these adverse effects seems to be played by oxidative stress, which is an excess of reactive oxygen species relative to the amount of reducing species (including antioxidants), the first line of defense against reactive oxygen species. The aim of this study was to document the oxidative stress caused by exposure to respirable particles <it>in vivo</it>, and to test whether exposed workers presented changes in their urinary levels for reducing species.</p> <p>Methods</p> <p>Bus depot workers (n = 32) exposed to particles and pollutants (respirable PM₄, organic and elemental carbon, particulate metal content, polycyclic aromatic hydrocarbons, NO_x, O₃) were surveyed over two consecutive days. We collected urine samples before and after each shift, and quantified an oxidative stress biomarker (8-hydroxy-2'-deoxyguanosine), the reducing capacity and a biomarker of PAH exposure (1-hydroxypyrene). We used a linear mixed model to test for associations between the oxidative stress status of the workers and their particle exposure as well as with their urinary level of reducing species.</p> <p>Results</p> <p>Workers were exposed to low levels of respirable PM₄(range 25-71 μg/m³). However, urinary levels of 8-hydroxy-2'-deoxyguanosine increased significantly within each shift and between both days for non-smokers. The between-day increase was significantly correlated (p < 0.001) with the concentrations of organic carbon, NO_x, and the particulate copper content. The within-shift increase in 8OHdG was highly correlated to an increase of the urinary reducing capacity (Spearman ρ = 0.59, p < 0.0001).</p> <p>Conclusions</p> <p>These findings confirm that exposure to components associated to respirable particulate matter causes a systemic oxidative stress, as measured with the urinary 8OHdG. The strong association observed between urinary 8OHdG with the reducing capacity is suggestive of protective or other mechanisms, including circadian effects. Additional investigations should be performed to understand these observations.</p

Leaf protein analysis during gibberellic and photoperiodic induction of flowering in <i>Arabidopsis thaliana</i>

Leaf proteins from Arabidopsis thaliana Landsberg erecta treated with gibberellin A₃ and different light regimes (continuous light, 16/8 h dark/light cycle and 8/16 h dark/light cycle) were analysed by two-dimensional gel electrophoresis. Qualitative differences between the controls and the treated plants were found, indicating that these treatments were responsible for the synthesis of specific proteins. A 35 kDa polypeptide is induced by gibberellin A₃ application and a 25 kDa polypeptide depends on the photoperiod

Analytical sensing platforms with inkjet printed electrodes

Disposable amperometric electrode chips enable the rapid, cost-effective and reliable monitoring of the concentration of analytes in fluidic samples. One example of high relevance in the health sector is the detection of hydrophilic antioxidants in fruit juices and biological fluids such as blood and saliva. In order to obtain highly reproducible electrodes at low cost and for small sample volumes, inkjet printing was used to prepare fully printed integrated electrode chips comprising a carbon nanotube working electrode, a carbon nanotube counter electrode and a silver or silver/silver chloride quasi-reference electrode. Silver was printed for the electrical connections and a UV curable dielectric ink was used to insulate the electrode connections and to precisely define the active electrode areas. The presented multi-layer based analytical sensing platforms support the recent general assessment that inkjet printing has reached the status of a large-scale production technique

Detection and characterization of GTP-binding proteins on tonoplast of Spinacia oleracea

Despite the growing interest in GTP-binding proteins and their role in higher plants, no compartimental analysis has been performed on tonoplast, until now. After successive extraction with a cushion of saccharose and a glycerol gradient, the tonoplast of Spinacia oleracea was checked by electron microscopy and the purity of the preparations verified by enzyme marker analyses. Guanosine triphosphate (GTP) binding assays were carried out on the extract with guanosine 5'[γ-thio] triphosphate, [35S] (GTPγ35S) as the non-hydrolysable substrate. A specific binding was observed and a KD of 0.3 mM was estimated by displacement curves. The characteristic enhancement by Mas 7 was also observed. Two dimensional gel electrophoresis of the GTP-binding test permitted localization of proteins between 20 and 55 kDa which bound specifically to GTPγ35S. Immunodetection was performed in the same experimental conditions with an antibody raised against the conserved consensus sequence of the GTP-binding site of the animal Gα subunit of the heterotrimeric G-Protein. It confirmed the presence of proteins of 41–44 kDa which correspond to those detected with the GTP-binding test