Sarah Moretti

Effects of Mountain Ultra-Marathon Running on ROS Production and Oxidative Damage by Micro-Invasive Analytic Techniques.

Purpose Aiming to gain a detailed insight into the physiological mechanisms involved under extreme conditions, a group of experienced ultra-marathon runners, performing the mountain Tor des Géants® ultra-marathon: 330 km trail-run in Valle d’Aosta, 24000 m of positive and negative elevation changes, was monitored. ROS production rate, antioxidant capacity, oxidative damage and inflammation markers were assessed, adopting micro-invasive analytic techniques. Methods Forty-six male athletes (45.04±8.75 yr, 72.6±8.4 kg, 1.76±0.05 m) were tested. Capillary blood and urine were collected before (Pre-), in the middle (Middle-) and immediately after (Post-) Race. Samples were analyzed for: Reactive Oxygen Species (ROS) production by Electron Paramagnetic Resonance; Antioxidant Capacity by Electrochemistry; oxidative damage (8-hydroxy-2-deoxy Guanosine: 8-OH-dG; 8-isoprostane: 8-isoPGF2α) and nitric oxide metabolites by enzymatic assays; inflammatory biomarkers (plasma and urine interleukin-6: IL-6-P and IL-6-U) by enzyme-linked immunosorbent assays (ELISA); Creatinine and Neopterin by HPLC, hematologic (lactate, glucose and hematocrit) and urine parameters by standard analyses. Results Twenty-five athletes finished the race, while twenty-one dropped out of it. A significant increase (Post-Race vs Pre) of the ROS production rate (2.20±0.27 vs 1.65±0.22 μmol.min-1), oxidative damage biomarkers (8-OH-dG: 6.32±2.38 vs 4.16±1.25 ng.mg-1 Creatinine and 8-isoPGF2α: 1404.0±518.30 vs 822.51±448.91 pg.mg-1Creatinine), inflammatory state (IL-6-P: 66.42±36.92 vs 1.29±0.54 pg.mL-1 and IL-6-U: 1.33±0.56 vs 0.71±0.17 pg.mL1) and lactate production (+190%), associated with a decrease of both antioxidant capacity (-7%) and renal function (i.e. Creatinine level +76%) was found. Conclusions The used micro-invasive analytic methods allowed us to perform most of them before, during and immediately after the race directly in the field, by passing the need of storing and transporting samples for further analysis. Considered altogether the investigated variables showed up that exhaustive and prolonged exercise not only promotes the generation of ROS but also induces oxidative stress, transient renal impairment and inflammation.

Oxidative stress response to acute hypobaric hypoxia and its association with indirect measurement of increased intracranial pressure: a field study

High altitude is the most intriguing natural laboratory to study human physiological response to hypoxic conditions. In this study, we investigated changes in reactive oxygen species (ROS) and oxidative stress biomarkers during exposure to hypobaric hypoxia in 16 lowlanders. Moreover, we looked at the potential relationship between ROS related cellular damage and optic nerve sheath diameter (ONSD) as an indirect measurement of intracranial pressure. Baseline measurement of clinical signs and symptoms, biological samples and ultrasonography were assessed at 262 m and after passive ascent to 3830 m (9, 24 and 72 h). After 24 h the imbalance between ROS production (+141%) and scavenging (−41%) reflected an increase in oxidative stress related damage of 50–85%. ONSD concurrently increased, but regression analysis did not infer a causal relationship between oxidative stress biomarkers and changes in ONSD. These results provide new insight regarding ROS homeostasis and potential pathophysiological mechanisms of acute exposure to hypobaric hypoxia, plus other disease states associated with oxidative-stress damage as a result of tissue hypoxia.

A novel application for cognitive evaluation in mountain ultramarathons: Olfactory assessment

OBJECTIVE Olfactory function, a cognitive impairment biomarker, was evaluated in mountain ultramarathon (MUM) runners during the Tor des Géants race (332.5 km with an overall altitude gain of 24,000 m; altitude range 330-3296 m above the sea). METHODS An Odor Identification Test was administered before (T0; n = 53), at 148.7 kms (T1; n = 32) and after the race (T2; n = 28). The effect of dehydration and sleep deprivation on olfactory function was assessed. Olfactory function was also assessed in non-MUM athletes and sedentary controls (C) at rest. RESULTS A majority of the athletes completed the olfactory test at all time intervals. Olfactory function decreased throughout the race (T0: 13.8 ± 1.9, T1: 13.7 ± 1.6, T2: 13.1 ± 1.8; T0 vs T2 P = .01). There was no relationship with race time or sleep deprivation on the sense of smell throughout the competition. However, there was a combined effect with decreased olfaction during the second half of the race, while a poor relationship was seen between olfaction and total body water at midterm (T1: rs = -0.427; P = .019), but not at baseline or after the race. MUM athletes had similar olfactory scores to C (13.8 ± 1.9 vs 13.7 ± 1.4) and non-MUM (13.8 ± 1.9 vs 13.9 ± 1.6) athletes. CONCLUSIONS This pilot study showed the feasibility of olfactory evaluation as a minimally invasive cognitive impairment assessment. The test can be used in logistically difficult environments, adding scientific value to this promising method. Although olfaction decreased after prolonged physical activity, further studies are warranted to make the relationship between cognition and external factors (eg, sleep deprivation, dehydration) more clear.

Oxidative Stress Assessment in Response to Ultraendurance Exercise: Thiols Redox Status and ROS Production according to Duration of a Competitive Race

Purpose. Response to an ultraendurance competitive race on thiols redox status, reactive oxygen species (ROS) production, and oxidative stress (OxS) was investigated according to duration. Methods. Twenty-four elite runners were examined: six completed 50 km and eighteen 100 km. Blood and urine samples were collected before and immediately after the race. Erythrocytes and plasma aminothiols by high-performance liquid chromatography, total antioxidant capacity (TAC), and OxS biomarkers (protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS), 8-isoprostane (8-iso-PGF2α), and 8-OH-2-deoxyguanosine (8-OH-dG)) by immunoenzymatic assays and ROS production by Electron Paramagnetic Resonance were assessed. Results. Significant increases (P between <0.05 and <0.0001) were recorded in plasma total and oxidized aminothiols concentration and TAC (P < 0.0001) only after 100 km: plasmatic (ROS production (+12 versus +29%), PC (+54 versus +115%), and TBARS (+28 versus +55%)) and urinary (8-OH-dG.creatinine−1 (+71 versus +158%) and 8-iso-PGF2α.creatinine−1 (+43 versus +135%)) concentrations for 50 and 100 km (duration 4 h 3′ versus 8 h 42′), respectively. Conclusion. Very prolonged ultraendurance exercise causes an increase in ROS production and OxS depending on specific biomarker examined but always linearly and directly related to exercise duration. Redox status of erythrocytes was preserved. A relationship between running performance and both prerace ROS production and antioxidant-redox status was found in 100 km race.

Supporting Physical and Cognitive Training for Preventing the Occurrence of Dementia Using an Integrated System: A Pilot Study

The project proposes a comprehensive preventive program of dementia in elderlies with minor cognitive disorders due to neurodegenerative diseases. The program combines physical and cognitive training, by means of an integrated technological system composed of a Virtual Environment, simulating daily activities, a smart garment measuring physiological parameters, a bicycle ergometer and tailoring the system to the specific patient’s status. Preliminary results confirm the feasibility of this intervention and appear promising in order to contrast age-related cognitive neurodegeneration.

Spirometry and oxidative stress after rebreather diving in warm water

Introduction Hyperbaric oxygen (HBO₂) therapy and use of enriched air can result in oxidative injury affecting the brain, lungs and eyes. HBO₂ exposure during diving can lead to a decrease in respiratory parameters. However, the possible effects of acute exposure to oxygen-enriched diving on subsequent spirometric performance and oxidative state in humans have not been recently described recently. We aim to investigate possible effects of acute (i) hyperbaric and (ii) hyperbaric hyperoxic exposure using scuba or closed-circuit rebreather (CCR) on subsequent spirometry and to assess the role of oxidative state after hyperoxic diving. Methods Spirometry and urine samples were obtained from six well-trained divers (males, mean ± SD, age: 43.33 ± 9.16 years; weight: 79.00 ± 4.90 kg; height: 1.77 ± 0.07 meters) before (CTRL) and after a dive breathing air, and after a dive using CCR (PO₂ 1.4). In the crossover design (two dives separated by six hours) each subject performed a 20-minute session of light underwater exercise at a depth of 15 meters in warm water (31-32°C). We measured urinary 8-isoprostane and 8-OH-2-deoxyguanosine evaluating lipid and DNA oxidative damages. Results Different breathing conditions (air vs. CCR) did not significantly affect spirometry. A significant increase of 8-OH-dG (1.85 ± 0.66 vs. 4.35 ± 2.12; P ⟨ 0.05) and 8-isoprostane (1.35 ± 0.20 vs. 2.59 ± 0.61; P ⟨ 0.05) levels after CCR dive with respect to the CTRL was observed. Subjects did not have any ill effects during diving. Conclusions Subjects using CCR showed elevated oxidative stress, but this did not correlate with a reduction in pulmonary function.

R(+)-Thioctic Acid Effects on Oxidative Stress and Peripheral Neuropathy in Type II Diabetic Patients: Preliminary Results by Electron Paramagnetic Resonance and Electroneurography

Objectives Diabetic neuropathy is the most common complication of diabetes. The idea of alterations in energy metabolism in diabetes is emerging. The biogenic antioxidant R(+)-thioctic acid has been successfully used in the treatment of diabetic polyneuropathic (DPN) patients. Methods The effects of R(+)-thioctic acid (1 tablet, 1.6 g) administration were evaluated in 12 DPN patients at baseline and at 15, 30, 60, and 120 administration days throughout the assessment of oxidative stress (OxS); ROS production rate by electron paramagnetic resonance (EPR) technique; and oxidative damage biomarkers (thiobarbituric acid reactive substances (TBARS) and protein carbonyls (PC)), electroneurography (ENG) and visual analogue scale. Results Supplementation induced significant changes (p < 0.05) at 30 and 60 days. ROS production rate up to −16%; TBARS (−31%), PC (−38%), and TAC up to +48%. Motor nerve conduction velocity in SPE and ulnar nerves (+22% and +16%) and sensor conduction velocity in sural and median nerves (+22% and +5%). Patients reported a general wellness sensation improvement (+35%) at 30 days: lower limb pain sensation (−40%) and upper limbs (−23%). Conclusion The results strongly indicate that an increased antioxidant capacity plays an important role in OxS, nerve conduction velocity, pain, and general wellness improvement. Nevertheless, the effects of the antioxidant compound were found positive up to 60 days. Then, a hormesis effect was observed. Novelty of the research would be a challenge for investigators to carefully address issues, including dose range factors, appropriate administration time, and targeting population to counteract possible “boomerang effects.” The great number of monitored parameters would firmly stress these conclusions.

Effects of Combined Physical and Cognitive Virtual Reality-Based Training on Cognitive Impairment and Oxidative Stress in MCI Patients: A Pilot Study

The growing elderly population and the increased incidence of mild cognitive impairment (MCI) and Alzheimer’s disease (AD) call for the improvement of the quality and the efficacy of the healthcare and social support services. Exercise and cognitive stimulation have been demonstrated to mitigate cognitive impairment and oxidative stress (OxS) has been recognized as a factor that contributes to the advancement of neurodegenerative diseases. Taking these aspects into account, the impact of a novel virtual reality (VR)-based program combining aerobic exercise and cognitive training has been evaluated in the pilot study proposed here. Ten patients (aged 73.3 ± 5.7 years) with MCI (Mini-Mental State Examination, MMSE: 23.0 ± 3.4) were randomly assigned to either 6 weeks physical and cognitive training (EXP) or control (CTR) group. Evaluations of cognitive profile, by a neuropsychological tests battery, and OxS, by collection of blood and urine samples, were performed before and at the end of the experimental period. The assessment of the patients’ opinions toward the intervention was investigated through questionnaires. EXP group showed a tendency towards improvements in the MMSE, in visual-constructive test and visuo-spatial tests of attention, while CTR worsened. EXP group showed a greater improvement than CTR in the executive test, memory functions and verbal fluency. No statistical significance was obtained when comparing within and between both the groups, probably due to small number of subjects examined, which amplifies the effect of the slight heterogeneity in scores recorded. Despite a greater worsening of Daily Living Activities tests, all participants reported a better performance in real life, thanks to the elicited self-perceived improvement. After training intervention OxS (i.e., reactive oxygen species (ROS) production, oxidative damage of lipids and DNA) decreased resulting in significantly (range p < 0.05–0.001) lower in EXP vs. CTR group. Although not conclusive, the recorded effects in the present study are promising and suggest that this proposal would be a useful tool in support of cognitive training reducing OxS too. However, further studies on larger scale samples of patients are needed.

Oxidative stress as a biomarker for monitoring treated celiac disease

Introduction: High levels of reactive oxygen species (ROS) and impaired antioxidant defense systems lead to oxidative stress (OxS) and tissue injury in different intestinal and extra intestinal conditions, including celiac disease (CD). The aim of the present study was to investigate the role and potential use of ROS and other biomarkers of OxS in the clinical management of CD. Methods: We collected duodenal specimens and blood samples from naïve patients (N‐CD), patients on a gluten free diet (GFD) including responders (CD‐GFD) and non‐responders (NRCD).We measured plasmatic ROS production (electron paramagnetic resonance, EPR), lipid peroxidation (thiobarbituric acid‐reactive substances, TBARS), protein oxidation (protein carbonyl, PC), total antioxidant capacity (TAC), nitric oxides and glutathione (GSH) in erythrocytes. Results: Fifty‐four patients affected by CD were enrolled (17 N‐CD, 18 CD‐GFD and 19 NRCD; 44 F; age 44 ± 13 years). A significant increase of plasmatic OxS biomarkers (ROS, peroxidated lipids, oxidized proteins, and nitrate concentrations) and decrease of antioxidant species (TAC and GSH levels) were found in NRCD and N‐CD compared to CD‐GFD. Comparably, a significant direct relationship between the severity of duodenal atrophy, ROS production rates and TBARS was found; conversely, TAC and GSH presented an inverse correlation. Discussion: OxS is involved in CD tissue damage and correlates with the degree of duodenal atrophy. These findings suggest the possible role of OxS biomarkers as indicators of CD activity during the clinical follow‐up.

Bioengineered gold nanoparticles targeted to mesenchymal cells from patients with bronchiolitis obliterans syndrome does not rise the inflammatory response and can be safely inhaled by rodents

Abstract The use of gold nanoparticles (GNPs) as drug delivery system represents a promising issue for diseases without effective pharmacological treatment due to insufficient local drug accumulation and excessive systemic toxicity. Bronchiolitis obliterans syndrome (BOS) represents about 70% of cases of chronic lung allograft dysfunction, the main challenge to long-term lung transplantation. It is believed that due to repeated insults to epithelial bronchiolar cells local inflammatory response creates a milieu that favors epithelial–mesenchymal transition and activation of local mesenchymal cells (MCs) leading to airway fibro-obliteration. In a previous work, we engineered GNPs loaded with the mammalian target of rapamycin inhibitor everolimus, specifically decorated with an antibody against CD44, a surface receptor expressed by primary MCs isolated from bronchoalveolar lavage of BOS patients. We proved in vitro that these GNPs (GNP-HCe) were able to specifically inhibit primary MCs without affecting the bronchial epithelial cell. In the present work, we investigated the effect of these bioengineered nanoconstructs on inflammatory cells, given that a stimulating effect on macrophages, neutrophils or lymphocytes is strongly unwanted in graft airways since it would foster fibrogenesis. In addition, we administered GNP-HCe by the inhalatory route to normal mice for a preliminary assessment of their pulmonary and peripheral (liver, spleen and kidney) uptake. By these experiments, an evaluation of tissue toxicity was also performed. The present study proves that our bioengineered nanotools do not rise an inflammatory response and, under the tested inhalatory conditions that were used, are non-toxic.