Segui questo link per vedere altri tipi di pubblicazioni sul tema: Active oxygen – Physiological effect.
Articoli di riviste sul tema "Active oxygen – Physiological effect"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Active oxygen – Physiological effect".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
Colon, Marcus, Andrew Hodgson, Eimear Donlon e James E. J. Murphy. "Effects of Competitive Triathlon Training on Telomere Length". Journal of Aging and Physical Activity 27, n. 4 (1 agosto 2019): 510–14. http://dx.doi.org/10.1123/japa.2018-0248.
Testo completoAbstract (sommario):
Telomeres act as a mitotic clock and telomere-related senescence has been linked to age-related physiological decline. There is increasing evidence lifestyle factors can influence telomere length (TL). The purpose of this study was to determine the effect of competitive triathlon training on TL. Seven competitive male triathletes and seven recreationally active males participated in the study. Relative TL was measured using quantitative polymerase chain reaction. Physiological parameters key to athletic performance such as maximal oxygen intake, lactate threshold, and running economy were also measured. Triathletes had longer telomeres than the recreationally active (1.257 ± 0.028 vs. 1.002 ± 0.014; p < .0001). Positive association was found between TL and maximal oxygen intake, lactate threshold, and running economy (R2 = .677, .683, and .696, respectively). This study indicates that competitive triathlon training buffers against age-related telomere shortening, and there is a correlation between exercise behaviors, higher maximal oxygen intake, and TL.
2
Madueno, Maria C., Vincent J. Dalbo, Joshua H. Guy, Kate E. Giamarelos, Tania Spiteri e Aaron T. Scanlan. "Reduced Fatigue in Passive Versus Active Recovery: An Examination of Repeated-Change-of-Direction Sprints in Basketball Players". International Journal of Sports Physiology and Performance 13, n. 8 (1 settembre 2018): 1034–41. http://dx.doi.org/10.1123/ijspp.2017-0831.
Testo completoAbstract (sommario):
Purpose: To investigate the physiological and performance effects of active and passive recovery between repeated-change-of-direction sprints. Methods: Eight semiprofessional basketball players (age: 19.9 [1.5] y; stature: 183.0 [9.6] cm; body mass: 77.7 [16.9] kg; body fat: 11.8% [6.3%]; and peak oxygen consumption: 46.1 [7.6] mL·kg−1·min−1) completed 12 × 20-m repeated-change-of-direction sprints (Agility 5-0-5 tests) interspersed with 20 seconds of active (50% maximal aerobic speed) or passive recovery in a randomized crossover design. Physiological and perceptual measures included heart rate, oxygen consumption, blood lactate concentration, and rating of perceived exertion. Change-of-direction speed was measured during each sprint using the change-of-direction deficit (CODD), with summed CODD time and CODD decrement calculated as performance measures. Results: Average heart rate (7.3 [6.4] beats·min−1; P = .010; effect size (ES) = 1.09; very likely) and oxygen consumption (4.4 [5.0] mL·kg−1·min−1; P = .12; ES = 0.77; unclear) were moderately greater with active recovery compared with passive recovery across sprints. Summed CODD time (0.87 [1.01] s; P = .07; ES = 0.76, moderate; likely) and CODD decrement (8.1% [3.7%]; P < .01; ES = 1.94, large; almost certainly) were higher with active compared with passive recovery. Trivial–small differences were evident for rating of perceived exertion (P = .516; ES = 0.19; unclear) and posttest blood lactate concentration (P = .29; ES = 0.40; unclear) between recovery modes. Conclusions: Passive recovery between repeated-change-of-direction sprints may reduce the physiological stress and fatigue encountered compared with active recovery in basketball players.
3
Carmeli, Eli, Pini Orbach, David T. Lowenthal, Joav Merrick e Raymond Coleman. "Long-Term Effects of Activity Status in the Elderly on Cardiorespiratory Capacity, Blood Pressure, Blood Lipids, and Body Composition: A Five-Year Follow-Up Study". Scientific World JOURNAL 3 (2003): 751–67. http://dx.doi.org/10.1100/tsw.2003.66.
Testo completoAbstract (sommario):
It is generally recognized that physical activity levels in the elderly do not remain constant over time, and typically there is a marked reduction in physical activities in the elderly. The long-term benefits of regular physical training programs in the elderly are still not fully understood. This is a study of 55 elderly healthy subjects (over 65 years old) and re-evaluated for the effects of different physical activity patterns (sedentary, moderately active, and highly active) on several physiological parameters (pre- and post-training) after a 5-year period (5.30 ± 1.14 years). Measurements included: body composition, blood lipid profiles, resting systolic and diastolic blood pressure, maximal oxygen uptake, and pulmonary function. Results indicated a larger decrease in maximal oxygen uptake (VO2max) in the group of elderly sedentary individuals (1.5 ± 0.5 l/min) compared to the moderately active (1.7 ± 0.6 l/min) and the highly active groups (1.9 ± 0.4 l/min). An active lifestyle was not sufficient to increase the physiological function of an individual.This study could not clearly demonstrate favorable differences for the physically active groups over the sedentary group with regard to several important physiological factors over the 5-year follow-up and it appears that the recommendation for, and the initiation of, adopting active lifestyles may not be sufficient on their own to significantly increase an individual's physiological functioning.
4
Reid, MB. "Reactive Oxygen and Nitric Oxide in Skeletal Muscle". Physiology 11, n. 3 (1 giugno 1996): 114–19. http://dx.doi.org/10.1152/physiologyonline.1996.11.3.114.
Testo completoAbstract (sommario):
Skeletal muscle produces oxygen radicals, nitric oxide, and a variety of redox-active derivatives that modulate muscle function under physiological conditions. In unfatigued muscle, reactive oxygen intermediates and nitric oxide exert opposing effects on excitation-contraction coupling. During strenuous exercise, oxidants accumulate in the tissue and accelerate the fatigue process.
5
Rubalcaba, Juan G., Wilco C. E. P. Verberk, A. Jan Hendriks, Bart Saris e H. Arthur Woods. "Oxygen limitation may affect the temperature and size dependence of metabolism in aquatic ectotherms". Proceedings of the National Academy of Sciences 117, n. 50 (30 novembre 2020): 31963–68. http://dx.doi.org/10.1073/pnas.2003292117.
Testo completoAbstract (sommario):
Both oxygen and temperature are fundamental factors determining metabolic performance, fitness, ecological niches, and responses of many aquatic organisms to climate change. Despite the importance of physical and physiological constraints on oxygen supply affecting aerobic metabolism of aquatic ectotherms, ecological theories such as the metabolic theory of ecology have focused on the effects of temperature rather than oxygen. This gap currently impedes mechanistic models from accurately predicting metabolic rates (i.e., oxygen consumption rates) of aquatic organisms and restricts predictions to resting metabolism, which is less affected by oxygen limitation. Here, we expand on models of metabolic scaling by accounting for the role of oxygen availability and temperature on both resting and active metabolic rates. Our model predicts that oxygen limitation is more likely to constrain metabolism in larger, warmer, and active fish. Consequently, active metabolic rates are less responsive to temperature than are resting metabolic rates, and metabolism scales to body size with a smaller exponent whenever temperatures or activity levels are higher. Results from a metaanalysis of fish metabolic rates are consistent with our model predictions. The observed interactive effects of temperature, oxygen availability, and body size predict that global warming will limit the aerobic scope of aquatic ectotherms and may place a greater metabolic burden on larger individuals, impairing their physiological performance in the future. Our model reconciles the metabolic theory with empirical observations of oxygen limitation and provides a formal, quantitative framework for predicting both resting and active metabolic rate and hence aerobic scope of aquatic ectotherms.
6
Molina-Sotomayor, Edgardo, Marcelo González Orb, Francisco Pradas de la Fuente, Giovanni Carozzi Figueroa, Antonio Sánchez-Oliver e José González-Jurado. "Effects of Cardiorespiratory Exercise on Cognition in Older Women Exposed to Air Pollution". International Journal of Environmental Research and Public Health 16, n. 2 (16 gennaio 2019): 245. http://dx.doi.org/10.3390/ijerph16020245.
Testo completoAbstract (sommario):
The aim was to analyze the effects of cardiorespiratory exercise and air pollution on cognition and cardiovascular markers in four groups of older women: the active/clean air group (AC), the active/polluted air group (AP), the sedentary/clean air group (SC), and the sedentary/polluted air group (SP). Active groups performed a training task based on progressive walking. Prior to and after the experiment, the following parameters were assessed: cognition, by Mini Mental State Examination (MMSE); maximum oxygen uptake (VO2max), estimated by the Six-Minute Walk Test (6mWT); heart rate (HR); and oxygen saturation (SpO2). There were significant differences (p < 0.05) between the AC and the SP in all the MMSE dimensions except “Registration”, and in all the physiological variables (VO2max, SpO2, HR). Aerobic exercise may be a protective factor against the effects that pollution have on cognition and on the mechanisms of oxygen transport.
7
Losnegard, Thomas, Martin Andersen, Matt Spencer e Jostein Hallén. "Effects of Active Versus Passive Recovery in Sprint Cross-Country Skiing". International Journal of Sports Physiology and Performance 10, n. 5 (luglio 2015): 630–35. http://dx.doi.org/10.1123/ijspp.2014-0218.
Testo completoAbstract (sommario):
Purpose:To investigate the effects of an active and a passive recovery protocol on physiological responses and performance between 2 heats in sprint cross-country skiing.Methods:Ten elite male skiers (22 ± 3 y, 184 ± 4 cm, 79 ± 7 kg) undertook 2 experimental test sessions that both consisted of 2 heats with 25 min between start of the first and second heats. The heats were conducted as an 800-m time trial (6°, >3.5 m/s, ~205 s) and included measurements of oxygen uptake (VO2) and accumulated oxygen deficit. The active recovery trial involved 2 min standing/walking, 16 min jogging (58% ± 5% of VO2peak), and 3 min standing/walking. The passive recovery trial involved 15 min sitting, 3 min walk/jog (~ 30% of VO2peak), and 3 min standing/walking. Blood lactate concentration and heart rate were monitored throughout the recovery periods.Results:The increased 800-m time between heat 1 and heat 2 was trivial after active recovery (effect size [ES] = 0.1, P = .64) and small after passive recovery (ES = 0.4, P = .14). The 1.2% ± 2.1% (mean ± 90% CL) difference between protocols was not significant (ES = 0.3, P = .3). In heat 2, peak and average VO2 was increased after the active recovery protocol.Conclusions:Neither passive recovery nor running at ~58% of VO2peak between 2 heats changed performance significantly.
8
Milovanova, Tatyana N., Veena M. Bhopale, Elena M. Sorokina, Jonni S. Moore, Thomas K. Hunt, Martin Hauer-Jensen, Omaida C. Velazquez e Stephen R. Thom. "Hyperbaric oxygen stimulates vasculogenic stem cell growth and differentiation in vivo". Journal of Applied Physiology 106, n. 2 (febbraio 2009): 711–28. http://dx.doi.org/10.1152/japplphysiol.91054.2008.
Testo completoAbstract (sommario):
We hypothesized that oxidative stress from hyperbaric oxygen (HBO2, 2.8 ATA for 90 min daily) exerts a trophic effect on vasculogenic stem cells. In a mouse model, circulating stem/progenitor cell (SPC) recruitment and differentiation in subcutaneous Matrigel were stimulated by HBO2and by a physiological oxidative stressor, lactate. In combination, HBO2and lactate had additive effects. Vascular channels lined by CD34+SPCs were identified. HBO2and lactate accelerated channel development, cell differentiation based on surface marker expression, and cell cycle entry. CD34+SPCs exhibited increases in thioredoxin-1 (Trx1), Trx reductase, hypoxia-inducible factors (HIF)-1, -2, and -3, phosphorylated mitogen-activated protein kinases, vascular endothelial growth factor, and stromal cell-derived factor-1. Cell recruitment to Matrigel and protein synthesis responses were abrogated by N-acetyl cysteine, dithioerythritol, oxamate, apocynin, U-0126, neutralizing anti-vascular endothelial growth factor, or anti-stromal cell-derived factor-1 antibodies, and small inhibitory RNA to Trx reductase, lactate dehydrogenase, gp91phox, HIF-1 or -2, and in mice conditionally null for HIF-1 in myeloid cells. By causing an oxidative stress, HBO2activates a physiological redox-active autocrine loop in SPCs that stimulates vasculogenesis. Thioredoxin system activation leads to elevations in HIF-1 and -2, followed by synthesis of HIF-dependent growth factors. HIF-3 has a negative impact on SPCs.
9
Dehghani, Hamed, Mohammad Ali Oghabian, Seyed Amir Hosein Batouli, Jalil Arab Kheradmand e Ali Khatibi. "Effect of Physiological Noise on Thoracolumbar Spinal Cord Functional Magnetic Resonance Imaging in 3T Magnetic Field". Basic and Clinical Neuroscience Journal 11, n. 6 (1 novembre 2020): 737–52. http://dx.doi.org/10.32598/bcn.11.6.1395.1.
Testo completoAbstract (sommario):
Introduction: Functional magnetic resonance imaging (fMRI) methods have been used to study sensorimotor processing in the spinal cord. However, these techniques confront unwanted noises to the measured signal from the physiological fluctuations. In the spinal cord imaging, most of the challenges are consequences of cardiac and respiratory movement artifacts that are considered as significant sources of noise, especially in the thoracolumbar region. In this study, we investigated the effect of each source of physiological noise and their contribution to the outcome of the analysis of the blood-oxygen-level-dependent signal in the human thoracolumbar spinal cord. Methods: Fifteen young healthy male volunteers participated in the study, and pain stimuli were delivered on the L5 dermatome between the two malleoli. Respiratory and cardiac signals were recorded during the imaging session, and the generated respiration and cardiac regressors were included in the general linear model for quantification of the effect of each of them on the task-analysis results. The sum of active voxels of the clusters was calculated in the spinal cord in three correction states (respiration correction only, cardiac correction only, and respiration and cardiac noise corrections) and analyzed with analysis of variance statistical test and receiver operating characteristic curve. Results: The results illustrated that cardiac noise correction had an effective role in increasing the active voxels (Mean±SD= 23.46±9.46) compared to other noise correction methods. Cardiac effects were higher than other physiological noise sources Conclusion: In summary, our results indicate great respiration effects on the lumbar and thoracolumbar spinal cord fMRI, and its contribution to the heartbeat effect can be a significant variable in the individual fMRI data analysis. Displacement of the spinal cord and the effects of this noise in the thoracolumbar and lumbar spinal cord fMRI results are significant and cannot be ignored.
10
Mikalački, Milena, Nebojša Čokorilo e Pedro Jesús Ruiz-Montero. "The effects of a pilates-aerobic program on maximum exercise capacity of adult women". Revista Brasileira de Medicina do Esporte 23, n. 3 (maggio 2017): 246–49. http://dx.doi.org/10.1590/1517-869220172303156004.
Testo completoAbstract (sommario):
ABSTRACT Introduction: Physical exercise such as the Pilates method offers clinical benefits on the aging process. Likewise, physiologic parameters may be improved through aerobic exercise. Methods: In order to compare the differences of a Pilates-Aerobic intervention program on physiologic parameters such as the maximum heart rate (HRmax), relative maximal oxygen consumption (relative VO2max) and absolute (absolute VOmax), maximum heart rate during maximal oxygen consumption (VO2max-HRmax), maximum minute volume (VE) and forced vital capacity (FVC), a total of 64 adult women (active group = 48.1 ± 6.7 years; control group = 47.2 ± 7.4 years) participated in the study. The physiological parameters, the maximal speed and total duration of test were measured by maximum exercise capacity testing through Bruce protocol. The HRmax was calculated by a cardio-ergometric software. Pulmonary function tests, maximal speed and total time during the physical test were performed in a treadmill (Medisoft, model 870c). Likewise, the spirometry analyzed the impact on oxygen uptake parameters, including FVC and VE. Results: The VO2max (relative and absolute), VE (all, P<0.001), VO2max-HRmax (P<0.05) and maximal speed of treadmill test (P<0.001) showed significant difference in the active group after a physical exercise interventional program. Conclusion: The present study indicates that the Pilates exercises through a continuous training program might significantly improve the cardiovascular system. Hence, mixing strength and aerobic exercises into a training program is considered the optimal mechanism for healthy aging.
11
Smith, Abbie E., Christopher M. Lockwood, Jordan R. Moon, Kristina L. Kendall, David H. Fukuda, Sarah E. Tobkin, Joel T. Cramer e Jeffrey R. Stout. "Physiological effects of caffeine, epigallocatechin-3-gallate, and exercise in overweight and obese women". Applied Physiology, Nutrition, and Metabolism 35, n. 5 (ottobre 2010): 607–16. http://dx.doi.org/10.1139/h10-056.
Testo completoAbstract (sommario):
The aim of this study was to evaluate the combined effects of a 10-week exercise program with ingestion of caffeine and epigallocatechin-3-gallate (EGCG) on body composition, cardiovascular fitness, and strength in overweight and obese women. In a double-blind, placebo-controlled approach, overweight and obese women (n = 27) were randomly assigned to treatment groups with exercise (an active-supplementing group with exercise (EX-Act) and a placebo group with exercise (EX-PL)) or without exercise (an active-supplementing group without exercise (NEX-Act) and a placebo group without exercise (NEX-PL)). All participants consumed 1 drink per day for 10 weeks; EX-Act and EX-PL participated in a concurrent endurance and resistance training program. Changes in body composition were assessed using a 4-compartment model. Changes in muscle mass (MM) were evaluated using a DXA-derived appendicular lean–soft tissue equation. There was a significant time × treatment interaction for MM (p = 0.026) and total cholesterol (TC) (p = 0.047), and a significant time × training interaction for peak oxygen consumption (p = 0.046) and upper-body and lower-body strength (p < 0.05). Significant differences between the EX groups and NEX groups for percentage change in MM and peak oxygen consumption, and upper-body and lower-body strength, were revealed. Clinical markers for hepatic and renal function revealed no adverse effects. TC significantly decreased for the active-supplementing groups (EX-Act, NEX-Act). The current study suggests that implementing a caffeine–EGCG-containing drink prior to exercise may improve MM, fitness, and lipid profiles in overweight women.
12
Cicogna, Francesca, Emilia Bramanti, Beatrice Campanella, Stefano Caporali, Luca Panariello, Caterina Cristallini, Randa Ishak, Niccoletta Barbani, Elisa Passaglia e Serena Coiai. "Surface Functionalization of Face Masks with Cold Plasma and Its Effect in Anchoring Polyphenols Extracted from Agri-Food". Molecules 27, n. 23 (6 dicembre 2022): 8632. http://dx.doi.org/10.3390/molecules27238632.
Testo completoAbstract (sommario):
To improve the capability of non-woven polypropylene-based fabric (NWF-PP) used for face mask production to retain active biomolecules such as polyphenols, the surface functionalization of NWF-PP–directly cut from face masks–was carried out by employing cold plasma with oxygen. The nature/structure of the functional groups, as well as the degree of functionalization, were evaluated by ATR-FTIR and XPS by varying the experimental conditions (generator power, treatment time, and oxygen flow). The effects of plasma activation on mechanical and morphological characteristics were evaluated by stress–strain measurements and SEM analysis. The ability of functionalized NWF-PP to firmly anchor polyphenols extracted from cloves was estimated by ATR-FTIR analysis, IR imaging, extractions in physiological solution, and OIT analysis (before and after extraction), as well as by SEM analysis. All the results obtained converge in showing that, although the plasma treatment causes changes–not only on the surface–with certain detriment to the mechanical performance of the NWF-PP, the incorporated functionalities are able to retain/anchor the active molecules extracted from the cloves, thus stabilizing the treated surfaces against thermo-oxidation even after prolonged extraction.
13
Valdenassi, Luigi, Marianno Franzini, Vincenzo Simonetti e Giovanni Ricevuti. "Oxygen-ozone therapy: paradoxical stimulation of ozone". Ozone Therapy 1, n. 1 (5 aprile 2016): 2. http://dx.doi.org/10.4081/ozone.2016.5837.
Testo completoAbstract (sommario):
After several years of scientific research and accurate clinical practice, the oxygen-ozone therapy continues to represent a method full of prospects and new opportunities. On this basis we present an updated review on basic mechanisms through which the ozone acts. Ozone, a molecule notable for its heterodoxy and atypicalness, has been regarded with suspicious for a long time since it was a possible generator of free radicals and correlated pathologies, but it is important distinguishing between the oxidative damage from free radicals, characterized by irreversible chemical modifications of the molecular target, and the physiological effects from free radicals (redox signaling), characterized on the other hand, by reversible chemical and selective alterations, which are potentially suitable to become an active part in the various metabolic regulation mechanisms, with positive effects on several pathologies.
14
Carmeli, Eli, Gadi Bartur, Sara Peleg, Shemuel Barchad e Jean-Jacques Vatine. "Does Passive Leg Activity Influence Oxygen Saturation and Activity in Sedentary Elderly Adults?" Scientific World JOURNAL 6 (2006): 1075–80. http://dx.doi.org/10.1100/tsw.2006.199.
Testo completoAbstract (sommario):
This study aimed to investigate whether any physiological changes might have a clinically significant effect on function in sedentary, institutionalized, older adults treated by a passive training program. A total of 18 subjects (mean age 60.7 ± 3.4) with intellectual disability (ID) participated. We measured SpO2 (arterial oxygen saturation) before, during, and after passive training, and used Barthel Index to measure daily living activities. The general trend indicated that inactive people with ID evidenced a continual increase in SpO2% levels and some functional gains during passive treatment, with superiority to manual passive treatment compared to mechanical active passive training. For current clinical practice, most sedentary patients who experience clinically significant deconditioning and desaturation can benefit from passive treatment.
15
Girard, Olivier, Romain Leuenberger, Sarah J. Willis, Fabio Borrani e Grégoire P. Millet. "Effects of Active Preconditioning With Local and Systemic Hypoxia on Submaximal Cycling". International Journal of Sports Physiology and Performance 17, n. 2 (1 febbraio 2022): 307–12. http://dx.doi.org/10.1123/ijspp.2021-0046.
Testo completoAbstract (sommario):
Purpose: The authors compared the effects of active preconditioning with local and systemic hypoxia during submaximal cycling. Methods: On separate visits, 14 active participants completed 4 trials. Each visit was composed of 1 preconditioning phase followed, after 40 minutes of rest, by 3 × 6-minute cycling bouts (intensity = 85% of critical power; rest = 6 min). The preconditioning phase consisted of 4 × 5-minute cycling bouts at 1.5 W·kg−1 (rest = 5 min) in 4 conditions: control (no occlusion and normoxia), blood flow restriction (60% of total occlusion), HYP (systemic hypoxia; inspired fraction of oxygen = 13.6%), and blood flow restriction + HYP (local and systemic hypoxia combined). Results: During the preconditioning phase, there were main effects of both systemic (all P < .014) and local hypoxia (all P ≤ .001) on heart rate, arterial oxygen saturation, leg discomfort, difficulty of breathing, and blood lactate concentration. Cardiorespiratory variables, gross efficiency, energy cost, and energy expenditure during the last minute of 6-minute cycling bouts did not differ between conditions (all P > .105). Conclusion: Local and systemic hypoxic stimuli, or a combination of both, during active preconditioning did not improve physiological responses such as cycling efficiency during subsequent submaximal cycling.
16
Al-Suhaimi, Ebtesam A., Noorah A. Al-Riziza e Reham A. Al-Essa. "Physiological and Therapeutical Roles of Ginger and Turmeric on Endocrine Functions". American Journal of Chinese Medicine 39, n. 02 (gennaio 2011): 215–31. http://dx.doi.org/10.1142/s0192415x11008762.
Testo completoAbstract (sommario):
The natural product ginger (Zingiber officinale) has active constituents gingerol, Shogaol and Zerumbone, while turmeric (Curcuma longa) contains three active major curcuminoids, namely, curcumin, demethoxycurcumin, and bisdemethoxycurcumin. They have the same scientific classification and are reported to have anti-inflammatory and many therapeutic effects. This article reviews the physiological and therapeutic effects of ginger and turmeric on some endocrine gland functions, and signal pathways involved to mediate their actions. With some systems and adipose tissue, ginger and turmeric exert their actions through some/all of the following signals or molecular mechanisms: (1) through reduction of high levels of some hormones (as: T4, leptin) or interaction with hormone receptors; (2) by inhibition of cytokines/adipokine expression; (3) acting as a potent inhibitor of reactive oxygen species (ROS)-generating enzymes, which play an essential role between inflammation and progression of diseases; (4) mediation of their effects through the inhibition of signaling transcription factors; and/or (5) decrease the proliferative potent by down-regulation of antiapoptotic genes, which may suppress tumor promotion by blocking signal transduction pathways in the target cells. These multiple mechanisms of protection against inflammation and oxidative damage make ginger and curcumin particularly promising natural agents in fighting the ravages of aging and degenerative diseases, and need to be paid more attention by studies.
17
Eggmann, Sabrina, Irina Irincheeva, Gere Luder, Martin L. Verra, André Moser, Caroline H. G. Bastiaenen e Stephan M. Jakob. "Cardiorespiratory response to early rehabilitation in critically ill adults: A secondary analysis of a randomised controlled trial". PLOS ONE 17, n. 2 (3 febbraio 2022): e0262779. http://dx.doi.org/10.1371/journal.pone.0262779.
Testo completoAbstract (sommario):
Introduction Early rehabilitation is indicated in critically ill adults to counter functional complications. However, the physiological response to rehabilitation is poorly understood. This study aimed to determine the cardiorespiratory response to rehabilitation and to investigate the effect of explanatory variables on physiological changes during rehabilitation and recovery. Methods In a prospectively planned, secondary analysis of a randomised controlled trial conducted in a tertiary, mixed intensive care unit (ICU), we analysed the 716 physiotherapy-led, pragmatic rehabilitation sessions (including exercise, cycling and mobilisation). Participants were previously functionally independent, mechanically ventilated, critically ill adults (n = 108). Physiological data (2-minute medians) were collected with standard ICU monitoring and indirect calorimetry, and their medians calculated for baseline (30min before), training (during physiotherapy) and recovery (15min after). We visualised physiological trajectories and investigated explanatory variables on their estimated effect with mixed-effects models. Results This study found a large range of variation within and across participants’ sessions with clinically relevant variations (>10%) occurring in more than 1 out of 4 sessions in mean arterial pressure, minute ventilation (MV) and oxygen consumption (VO2), although early rehabilitation did not generally affect physiological values from baseline to training or recovery. Active patient participation increased MV (mean difference 0.7l/min [0.4–1.0, p<0.001]) and VO2 (23ml/min [95%CI: 13–34, p<0.001]) during training when compared to passive participation. Similarly, session type ‘mobilisation’ increased heart rate (6.6bpm [2.1–11.2, p = 0.006]) during recovery when compared to ‘exercise’. Other modifiable explanatory variables included session duration, mobilisation level and daily medication, while non-modifiable variables were age, gender, body mass index and the daily Sequential Organ Failure Assessment. Conclusions A large range of variation during rehabilitation and recovery mirrors the heterogenous interventions and patient reactions. This warrants close monitoring and individual tailoring, whereby the best option to stimulate a cardiorespiratory response seems to be active patient participation, shorter session durations and mobilisation. Trial registration German Clinical Trials Register (DRKS) identification number: DRKS00004347, registered on 10 September 2012.
18
Jiang, Dan, Bin Lu, Liantao Liu, Wenjing Duan, Li Chen, Jin Li, Ke Zhang et al. "Exogenous melatonin improves salt stress adaptation of cotton seedlings by regulating active oxygen metabolism". PeerJ 8 (11 dicembre 2020): e10486. http://dx.doi.org/10.7717/peerj.10486.
Testo completoAbstract (sommario):
Melatonin is a small-molecule indole hormone that plays an important role in participating in biotic and abiotic stress resistance. Melatonin has been confirmed to promote the normal development of plants under adversity stress by mediating physiological regulation mechanisms. However, the mechanisms by which exogenous melatonin mediates salt tolerance via regulation of antioxidant activity and osmosis in cotton seedlings remain largely unknown. In this study, the regulatory effects of melatonin on reactive oxygen species (ROS), the antioxidant system, and osmotic modulators of cotton seedlings were determined under 0–500 µM melatonin treatments with salt stress induced by 150 mM NaCl treatment. Cotton seedlings under salt stress exhibited an inhibition of growth, excessive hydrogen peroxide (H2O2), superoxide anion (O2−), and malondialdehyde (MDA) accumulations in leaves, increased activity levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and elevated ascorbic acid (AsA) and glutathione (GSH) content in leaves. However, the content of osmotic regulators (i.e., soluble sugars and proteins) in leaves was reduced under salt stress. This indicates high levels of ROS were produced, and the cell membrane was damaged. Additionally, osmotic regulatory substance content was reduced, resulting in osmotic stress, which seriously affected cotton seedling growth under salt stress. However, exogenous melatonin at different concentrations reduced the contents of H2O2, O2−, and MDA in cotton leaves, increased the activity of antioxidant enzymes and the content of reductive substances (i.e., AsA and GSH), and promoted the accumulation of osmotic regulatory substances in leaves under salt stress. These results suggest that melatonin can inhibit ROS production in cotton seedlings, improve the activity of the antioxidant enzyme system, raise the content of osmotic regulation substances, reduce the level of membrane lipid peroxidation, and protect the integrity of the lipid membrane under salt stress, which reduces damage caused by salt stress to seedlings and effectively enhances inhibition of salt stress on cotton seedling growth. These results indicate that 200 µM melatonin treatment has the best effect on the growth and salt tolerance of cotton seedlings.
19
Guseynov, Nidjat A., Marina H. Hammouri, Alexandr A. Muraev, Sergey Y. Ivanov, Elena A. Lukianova, Anna S. Klimenko e Mohammad A. Noeerazlighi. "Local hardware hypothermia influence on the physiological processes". RUDN Journal of Medicine 26, n. 3 (15 dicembre 2022): 243–58. http://dx.doi.org/10.22363/2313-0245-2022-26-3-243-258.
Testo completoAbstract (sommario):
Relevance. Cold vasodilation is a response to a decrease in local and general temperature. Dose-controlled hypothermia is a therapeutic method for treating various pathological processes. Materials and Methods. In our study, we analyzed various indicators of the general condition of the human body under the influence of local controlled hypothermia. The study involved 25 healthy volunteers from the age of 21 to 34, including 14 males and 11 females. The study was carried out at a constant temperature of 25 ºС, relative humidity of 30 ± 5%, and an atmospheric pressure of 765mm Hg in silence and moderate illumination. The instruments of these indicators were bio-impedancemetry, angioscanning, as well as general thermometry. We also performed local thermometry of the buccal mucosa to identify temperature correlations between local hypothermia and buccal mucosa temperature. Local сontrolled hypothermia of the face was carried out by applying an elastic mask to the subject’s face. The mask had a system of irrigation tubes connected to the «ViTherm» device, which cooled the liquid and maintained its circulation. Due to the circulation of the cooled liquid in the mask the face was cooled. The mask covered the parotid-chewing, buccal, zygomatic, and infraorbital regions on the right and left. LCG lasted 50 minutes, and the circulating fluid temperature was 18 ºС. Results and Discussion. The effect of local controlled hypothermia at 18-20 °C did not affect vital signs in healthy adults: active cell mass, electrical reactance, extracellular fluid, oxygen saturation, the duration of systole. pulse. general temperature. At the same time, a decrease in tissue hydration was recorded. The revealed physiological effect of local hypothermia justifies using this temperature regime to reduce postoperative edema. Conclusion. Due to the absence of negative effects of local controlled hypothermia on the vital signs of the human body, the development and application of this tool in clinical practice, including the dental surgeon. is relevant.
20
Li, Ying Xia, Suo Zhou, Feng Juan Zhao, Yan Liu, Pan Pan Fan e Guang Ce Wang. "Physiological responses of Porphyra haitanesis to different copper and zinc concentrations". Brazilian Journal of Oceanography 58, n. 4 (dicembre 2010): 261–67. http://dx.doi.org/10.1590/s1679-87592010000400001.
Testo completoAbstract (sommario):
In the present study, several physiological responses of the red marine alga Porphyra haitanesis to elevated concentrations of copper (up to 50 μM) and zinc (up to 100 μM) were investigated. Our results showed that the effects of Cu2+ and Zn2+ on growth, photosynthetic pigments (chlorophylls and carotenoids), phycobiliprotein and metabolism (the fluorescence emission spectra and the activities of photosystemII) did not follow the same pattern. The relative growth rate was inhibited by different concentrations of Cu2+, and was slightly increased at lower concentrations (up to 10 μM) and inhibited at higher Zn2+concentrations. On the other hand, the phycoerythrin contents were slightly increased at relatively low concentrations (up to 1 μM Cu2+ or 20 μM Zn2+) and inhibited by high Cu2+ and Zn2+ concentrations. Moreover, photosynthesis and respiration showed an increase in the amount of oxygen exchange in response to relatively low Cu2+ (up to 1 μM) and Zn2+ concentrations (up to 10 μM), and a reduction to relatively high Cu2+ and Zn2+ concentrations. Oxygen evolution was more sensitive than oxygen uptake to Cu2+ and Zn2+. In addition, the photoreductive activities and fluorescence emission of photosystem II (PS II) were enhanced by lower concentrations of Cu2+ (up to 0.1 μM) and Zn2+ (up to 10 μM) and inhibited by higher concentrations. Furthermore, the intensity of chlorophyll a fluorescence and the active PSII reaction centers followed a similar pattern in response to elevated concentrations of Cu2+ and Zn2+. These results suggest that lower concentrations of Cu2+ and Zn2+ affected the metabolism of P. haitanesis, which was inhibited by higher concentrations of these metals.
21
Zhang, Shuangxia, Yan Liu e Bo Liu. "Highly Active Nano-Reactor for Responding Tumor Microenvironment and Antitumor Therapy". Technology in Cancer Research & Treatment 21 (gennaio 2022): 153303382210956. http://dx.doi.org/10.1177/15330338221095670.
Testo completoAbstract (sommario):
The tumor microenvironment is complex and changeable, so the design of a nano-delivery system for the tumor microenvironment has attracted wide attention. Based on this, we designed an intelligent nano-reactor for the characteristics of acidic pH and hypoxia in the tumor microenvironment. Firstly, the silver nano-balls were synthesized by the biological template method, which exhibited a good photothermal conversion efficiency and can realize the photothermal treatment of tumor sites. Subsequently, the hypoxic prodrug tirapazamine (TPZ) and polydopamine (PDA) for chemotherapy were self-assembled. After PDA arrived at the tumor site (pH 5.5) from the normal physiological environment (pH 7.4), the hypoxic prodrug TPZ was released in pH response by PDA. Subsequently, TPZ selectively induced obvious cell damage under tumor hypoxia stimulation but had no toxic effect on normal cells under normal oxygen. In addition, the nano-converter was loaded with iRGD on the surface, which enhanced the targeted delivery of the nano-reactor to achieve a highly effective antitumor effect. The nano-reactor was capable of combining photothermal/chemotherapy therapy. Importantly, it can selectively kill tumor cells without damaging normal cells based on the characteristics of the tumor microenvironment, with high bio-safety and clinical transformation potential.
22
Krebs, Patricia, Warren Eickelberg, Hans Krobath e Ingrid Baruch. "Effects of Physical Exercise on Peripheral Vision and Learning in Children with Spina Bifida Manifesta". Perceptual and Motor Skills 68, n. 1 (febbraio 1989): 167–74. http://dx.doi.org/10.2466/pms.1989.68.1.167.
Testo completoAbstract (sommario):
The purpose of this research was to investigate the effects of active exercise of the arms on various physiological, perceptual, and cognitive parameters of children with spina bifida manifesta who were aged 9 to 12 yr. Following a 5-min. rest interval, subjects were either not exercised (control days) for a 6-min. period or were exercised (experimental days) for a 6-min. period. Cardiac measures, respiratory function, peripheral vision, and figural learning trials were recorded after exercise. Wilcoxon matched-pairs signed rank tests were computed on the means of the exercise and no-exercise conditions for each measure. Six minutes of active exercise resulted in significant increases in peripheral vision, respiratory and cardiac measures and significant decreases in figural learning trials for these children. A floor effect was noted for the figural learning test. It was concluded that exercise increased blood flow through the lungs allowing for greater oxygen diffusion in the brain and other facilitatory effects resulting in more effective cerebral activity. Curriculum revisions for such children seem to indicate the importance of activity in facilitating subsequent learning.
23
Silkstone, Gary G. A., Rebecca S. Silkstone, Michael T. Wilson, Michelle Simons, Leif Bülow, Kristian Kallberg, Khuanpiroon Ratanasopa et al. "Engineering tyrosine electron transfer pathways decreases oxidative toxicity in hemoglobin: implications for blood substitute design". Biochemical Journal 473, n. 19 (27 settembre 2016): 3371–83. http://dx.doi.org/10.1042/bcj20160243.
Testo completoAbstract (sommario):
Hemoglobin (Hb)-based oxygen carriers (HBOC) have been engineered to replace or augment the oxygen-carrying capacity of erythrocytes. However, clinical results have generally been disappointing due to adverse side effects linked to intrinsic heme-mediated oxidative toxicity and nitric oxide (NO) scavenging. Redox-active tyrosine residues can facilitate electron transfer between endogenous antioxidants and oxidative ferryl heme species. A suitable residue is present in the α-subunit (Y42) of Hb, but absent from the homologous position in the β-subunit (F41). We therefore replaced this residue with a tyrosine (βF41Y, Hb Mequon). The βF41Y mutation had no effect on the intrinsic rate of lipid peroxidation as measured by conjugated diene and singlet oxygen formation following the addition of ferric(met) Hb to liposomes. However, βF41Y significantly decreased these rates in the presence of physiological levels of ascorbate. Additionally, heme damage in the β-subunit following the addition of the lipid peroxide hydroperoxyoctadecadieoic acid was five-fold slower in βF41Y. NO bioavailability was enhanced in βF41Y by a combination of a 20% decrease in NO dioxygenase activity and a doubling of the rate of nitrite reductase activity. The intrinsic rate of heme loss from methemoglobin was doubled in the β-subunit, but unchanged in the α-subunit. We conclude that the addition of a redox-active tyrosine mutation in Hb able to transfer electrons from plasma antioxidants decreases heme-mediated oxidative reactivity and enhances NO bioavailability. This class of mutations has the potential to decrease adverse side effects as one component of a HBOC product.
24
Li, Shuisheng, Baoxin Zhang e Pingjun Ma. "THE RELIEVING EFFECT OF SUN-DRIED PROTEIN TONIC ON SPORTS FATIGUE". Revista Brasileira de Medicina do Esporte 27, spe2 (giugno 2021): 95–98. http://dx.doi.org/10.1590/1517-8692202127022020_0141.
Testo completoAbstract (sommario):
ABSTRACT Fatigue is a comprehensive process that involves many physiological and biochemical factors. It is a normal physiological reaction when human physical or mental activities reach a certain level. In recent years, it has been verified that free radicals are closely related to exercise-induced fatigue. Cardamine bursa purified selenoprotein has good oxygen-free radical scavenging ability and anti-lipid peroxide. It could protect mitochondria, liver, and red blood cells from peroxide injury. Therefore, it was speculated that the purification of selenoprotein Cardamine may play an active role in attenuating exercise-induced fatigue by scavenging free radicals. This study cleared the selenite protein Capsella bursa (SPC) as a research object, and evaluated its structural characteristics in relieving exercise-induced fatigue. The selenoprotein index system for exercise-induced fatigue was constructed by combining two AHP methods, principal component analysis and factor analysis. Purity, subunit composition, amino acid composition and RCM content were evaluated. The corresponding RCM protein was preliminarily predicted. The results showed that SPCH could significantly prolong the swimming time (P <0.01), improve the lactate clearance capacity (P <0.01), increase the glycogen content of the liver (P <0.01), and reduce the level of the BUN (P <0.05). SPCH has a good effect in relieving exercise-induced fatigue in mice, so it can be considered for development as a nutritional supplement to alleviate exercise-induced fatigue.
25
Hafedh, Hanen, Maamer Slimani, Bianca Miarka, Ramzi Bettayeb e Nicola Luigi Bragazzi. "Effects of Terbutaline Sulfate on Physiological and Biomechanical as Well as Perceived Exertion in Healthy Active Athletes: A Pilot Study". Journal of Human Kinetics 69, n. 1 (18 ottobre 2019): 169–78. http://dx.doi.org/10.2478/hukin-2018-0097.
Testo completoAbstract (sommario):
Abstract This study aimed to investigate the effects of beta2‐agonist terbutaline sulfate (TER) at a supra‐therapeutic dose (8 mg) on aerobic exercise performance. Twelve (6 females and 6 males) amateur athletes familiarized with all experimental procedures had their anthropometric data obtained on day 1. On days 2 and 3 either 8 mg of TER or a placebo (PLA) was administered orally (double‐blind manner) to participants who had rested for 3 h prior to aerobic exercise performance 20 m multistage fitness test (MSFT)]. This test was used to predict maximal oxygen uptake (VO2max) and velocity at which VO2max occurs (vVO2max). The Borg rating of perceived exertion (RPE), cardiovascular variables [heart rate (HR) and blood pressure (BP)] and blood glucose concentration [BGC] were obtained 15 min pre‐ and immediately post‐MSFT. Significant mean group differences were reported between PLA and TER groups (p < 0.05), respectively, in the RPE (15.6 ± 1.2 vs. 17.3 ± 1.5 a.u.), maximum heart rate (HRmax: 191.2 ± 7.1 vs. 197.2 ± 8.6 bpm) and BGC (118.4 ± 18.3 vs. 141.2 ± 15.8 mg/dL) post‐MSFT. The main effect of gender (male vs. female) in TER and PLA groups (p< 0.05) was observed, with higher estimated VO2max, vVO2max, HRmax and a lower mean HR pre‐test in male than female athletes. For these reasons, the inclusion of TER in the Prohibited List should be re‐discussed because of the lack of ergogenic effects.
26
Danek, Natalia, Kamil Michalik, Marcin Smolarek e Marek Zatoń. "Acute Effects of Using Added Respiratory Dead Space Volume in a Cycling Sprint Interval Exercise Protocol: A Cross-Over Study". International Journal of Environmental Research and Public Health 17, n. 24 (18 dicembre 2020): 9485. http://dx.doi.org/10.3390/ijerph17249485.
Testo completoAbstract (sommario):
Background: The aim of the study was to compare acute physiological, biochemical, and perceptual responses during sprint interval exercise (SIE) with breathing through a device increasing added respiratory dead space volume (ARDSV) and without the device. Methods: The study involved 11 healthy, physically active men (mean maximal oxygen uptake: 52.6 ± 8.2 mL∙kg1∙min−1). During four visits to a laboratory with a minimum interval of 72 h, they participated in (1) an incremental test on a cycle ergometer; (2) a familiarization session; (3) and (4) cross-over SIE sessions. SIE consisted of 6 × 10-s all-out bouts with 4-min active recovery. During one of the sessions the participants breathed through a 1200-mL ARDSv (SIEARDS). Results: The work performed was significantly higher by 4.4% during SIEARDS, with no differences in the fatigue index. The mean respiratory ventilation was significantly higher by 13.2%, and the mean oxygen uptake was higher by 31.3% during SIEARDS. Respiratory muscle strength did not change after the two SIE sessions. In SIEARDS, the mean pH turned out significantly lower (7.26 vs. 7.29), and the mean HCO3– concentration was higher by 7.6%. Average La− and rating of perceived exertion (RPE) did not differ between the sessions. Conclusions: Using ARDSV during SIE provokes respiratory acidosis, causes stronger acute physiological responses, and does not increase RPE.
27
Ziyadeh, F. N., e Z. S. Agus. "Benzodiazepines inhibit transport-related oxygen consumption in thick ascending limb". American Journal of Physiology-Cell Physiology 255, n. 3 (1 settembre 1988): C385—C392. http://dx.doi.org/10.1152/ajpcell.1988.255.3.c385.
Testo completoAbstract (sommario):
Specific binding sites for benzodiazepines (BZD) have been identified in several nonneuronal tissues including the kidney where they are localized predominantly to the tubular epithelium of the thick ascending limb of Henle's loop (TALH). The physiological function of these nonneuronal (peripheral) BZD-binding sites is undefined, but it has been suggested that they may represent receptors for putative endogenous ligands that may modulate cell function. In the current study, we examined the in vitro effects of diazepam and Ro5-4864, a specific peripheral BZD-receptor agonist, on the oxygen consumption of medullary TALH tubule suspensions of rabbit kidney. Maximal inhibition of total oxygen consumption was achieved at a dose of 5 X 10(-4) M of either agent. On average, diazepam and Ro5-4864 reduced total oxygen consumption by 41 and 44%, respectively. The predominant inhibition was in the ouabain-sensitive component of oxygen consumption, which suggests that BZDs inhibit active sodium-chloride transport in the TALH. To assess whether this inhibition depends on sodium uptake, TALH tubules were pretreated with amphotericin B (2 X 10(-6) M) to enhance sodium uptake and stimulate basal oxygen consumption; subsequent addition of Ro5-4864 (5 X 10(-4) M) still reduced oxygen consumption to a residual value that was not different from that in TALH tubules treated with Ro5-4864 but without pretreatment with amphotericin B. This suggests that BZD inhibition of transport-related oxygen consumption is not caused by diminution of sodium uptake into cells and thus appears to be distinct from the effect of furosemide.(ABSTRACT TRUNCATED AT 250 WORDS)
28
Drafi, Frantisek, Katarina Bauerova, Viera Kuncirova, Silvester Ponist, Danica Mihalova, Tatiana Fedorova, Juraj Harmatha e Radomir Nosal. "Pharmacological influence on processes of adjuvant arthritis: effect of the combination of an antioxidant active substance with methotrexate". Interdisciplinary Toxicology 5, n. 2 (9 novembre 2012): 84–91. http://dx.doi.org/10.2478/v10102-012-0015-4.
Testo completoAbstract (sommario):
Abstract Oxygen metabolism has an important role in the pathogenesis of rheumatoid arthritis. A certain correlation was observed between oxidative stress, arthritis and the immune system. Reactive oxygen species produced in the course of cellular oxidative phosphorylation and by activated phagocytic cells during oxidative burst, exceed the physiological buffering capacity and result in oxidative stress. The excessive production of ROS can damage protein, lipids, nucleic acids, and matrix components. Patients with rheumatoid arthritis have an altered antioxidant defense capacity barrier. In the present study the effect of substances with antioxidative properties, i.e. pinosylvin and carnosine, was determined in monotherapy for the treatment of adjuvant arthritis (AA). Moreover carnosine was evaluated in combination therapy with methotrexate. Rats with AA were administered first pinosylvin (30 mg/kg body mass daily per os), second carnosine (150 mg/kg body mass daily per os) in monotherapy for a period of 28 days. Further, rats with AA were administered methotrexate (0.3 mg/kg body mass 2-times weekly per os), and a combination of methotrexate+carnosine, with the carnosine dose being the same as in the previous experiment. Parameters, i.e. changes in hind paw volume and arthritic score were determined in rats as indicators of destructive arthritis-associated clinical changes. Plasmatic levels of TBARS and lag time of Fe2+- induced lipid peroxidation (tau-FeLP) in plasma and brain were specified as markers of oxidation. Plasmatic level of CRP and activity of γ-glutamyltransferase (GGT) in spleen and joint were used as inflammation markers. In comparison to pinosylvin, administration of carnosine monotherapy led to a significant decrease in the majority of the parameters studied. In the combination treatment with methotrexate+carnosine most parameters monitored were improved more remarkably than by methotrexate alone. Carnosine can increase the disease-modifying effect of methotrexate treatment in rat AA.
29
Esquius, Laura, Ramon Segura, Guillermo R. Oviedo, Marta Massip-Salcedo e Casimiro Javierre. "Effect of Almond Supplementation on Non-Esterified Fatty Acid Values and Exercise Performance". Nutrients 12, n. 3 (27 febbraio 2020): 635. http://dx.doi.org/10.3390/nu12030635.
Testo completoAbstract (sommario):
Several studies have investigated the effects of fat intake before exercise on subsequent substrate oxidation and exercise performance. While some studies have reported that unsaturated fatty acid supplementation slightly increases fat oxidation, the changes have not been reflected in the maximum oxygen uptake or in other performance and physiological parameters. We selected almonds as a fatty acid (FA) source for acute supplementation and investigated their effect on non-esterified fatty acid (NEFA) values and exercise performance. Five physically active male subjects (age 32.9 ± 12.7 years, height 178.5 ± 3.3 cm, and weight 81.3 ± 9.7 kg) were randomly assigned to take an almond or placebo supplement 2 h before participating in two cycling resistance training sessions separated by an interval of 7–10 days. Their performance was evaluated with a maximal incremental test until exhaustion. Blood samples collected before, during, and after testing were biochemically analysed. The results indicated a NEFA value average increase of 0.09 mg·dL−1 (95% CI: 0.05–0.14; p < 0.001) after active supplement intake and enhanced performance (5389 ± 1795 W vs. placebo 4470 ± 2053 W, p = 0.043) after almond supplementation compared to the placebo. The almond supplementation did not cause gastrointestinal disturbances. Our study suggests that acute almond supplementation 2 h before exercise can improve performance in endurance exercise in trained subjects.
30
Abrantes, Catarina, Susana Martins, Ana Pereira, Fernando Policarpo, Isabel Machado e Nelson Sousa. "Physiological Exercise and Post‐Exercise Effects of Inverse Sequences of Combined Bench‐Step Aerobics and Resistance Exercise". Journal of Human Kinetics 77, n. 1 (30 gennaio 2021): 61–70. http://dx.doi.org/10.2478/hukin-2021-0011.
Testo completoAbstract (sommario):
Abstract The purpose of this study was to compare the effects of using inverse sequences of combined bench-step aerobics and resistance exercise on cardiorespiratory, hemodynamic and perceptual variables during exercise and one-hour post-exercise. The tested sequences were bench-step aerobics immediately before and immediately after resistance exercise. Thirteen apparently healthy and physically active women (age = 21.9 ± 6.1 years, body height = 160 ± 0.1 cm, body mass = 58.8 ± 7.5 kg, estimated fat mass = 17.2 ± 2.0% and estimated maximal oxygen uptake = 37.5 ± 2.6 mL∙kg-1∙min-1) performed a 20-minute bench-step aerobics routine, immediately before (STEP_RES) and after (RES_STEP) resistance exercise. Oxygen uptake and heart rate were continuously measured, systolic and diastolic blood pressure, body temperature and perceived exertion were measured at rest, immediately after each type of exercise and at 15, 30, 45 and 60 min after exercise. When resistance exercise was performed first (RES_STEP), oxygen uptake was higher (23.2 ± 3.9 vs. 20.5 ± 4.8 mL∙kg-1∙min-1), but the heart rate (164.5 ± 9.1 vs. 173.9 ± 11.7 bpm) and body temperature (36.5 ± 0.4 vs. 37.6 ± 0.6 ºC) were lower. In both sequences, the type of exercise performed first was pointed out with a lower perceived exertion or lower perceived intensity. Exercise and 60-min post-exercise blood pressure had a similar response in both sequences, and systolic blood pressure along with diastolic blood pressure were lower than pre-exercise from 30 min until 60 min post-exercise. The results suggest that the sequence affected oxygen uptake and perceived exertion during exercise and that this total workload, despite the sequence, promoted a post-exercise blood pressure decrease in normotensive participants.
31
Manchado-Gobatto, Fúlvia Barros, Ricardo Silva Torres, Anita Brum Marostegan, Felipe Marroni Rasteiro, Charlini Simoni Hartz, Marlene Aparecida Moreno, Allan Silva Pinto e Claudio Alexandre Gobatto. "Complex Network Model Reveals the Impact of Inspiratory Muscle Pre-Activation on Interactions among Physiological Responses and Muscle Oxygenation during Running and Passive Recovery". Biology 11, n. 7 (25 giugno 2022): 963. http://dx.doi.org/10.3390/biology11070963.
Testo completoAbstract (sommario):
Although several studies have focused on the adaptations provided by inspiratory muscle (IM) training on physical demands, the warm-up or pre-activation (PA) of these muscles alone appears to generate positive effects on physiological responses and performance. This study aimed to understand the effects of inspiratory muscle pre-activation (IMPA) on high-intensity running and passive recovery, as applied to active subjects. In an original and innovative investigation of the impacts of IMPA on high-intensity running, we proposed the identification of the interactions among physical characteristics, physiological responses and muscle oxygenation in more and less active muscle to a running exercise using a complex network model. For this, fifteen male subjects were submitted to all-out 30 s tethered running efforts preceded or not preceded by IMPA, composed of 2 × 15 repetitions (1 min interval between them) at 40% of the maximum individual inspiratory pressure using a respiratory exercise device. During running and recovery, we monitored the physiological responses (heart rate, blood lactate, oxygen saturation) and muscle oxygenation (in vastus lateralis and biceps brachii) by wearable near-infrared spectroscopy (NIRS). Thus, we investigated four scenarios: two in the tethered running exercise (with or without IMPA) and two built into the recovery process (after the all-out 30 s), under the same conditions. Undirected weighted graphs were constructed, and four centrality metrics were analyzed (Degree, Betweenness, Eigenvector, and Pagerank). The IMPA (40% of the maximum inspiratory pressure) was effective in increasing the peak and mean relative running power, and the analysis of the complex networks advanced the interpretation of the effects of physiological adjustments related to the IMPA on exercise and recovery. Centrality metrics highlighted the nodes related to muscle oxygenation responses (in more and less active muscles) as significant to all scenarios, and systemic physiological responses mediated this impact, especially after IMPA application. Our results suggest that this respiratory strategy enhances exercise, recovery and the multidimensional approach to understanding the effects of physiological adjustments on these conditions.
32
Schellhorn, Herb E., e Hosni M. Hassan. "Response of hydroperoxidase and superoxide dismutase deficient mutants of Escherichia coli K-12 to oxidative stress". Canadian Journal of Microbiology 34, n. 10 (1 ottobre 1988): 1171–76. http://dx.doi.org/10.1139/m88-206.
Testo completoAbstract (sommario):
In Escherichia coli, the coordinate action of two antioxidant enzymes, superoxide dismutase and hydroperoxidase (catalase), protect the cell from the deleterious effects of oxyradicals generated during normal aerobic respiration. To evaluate the relative importance of these two classes of enzymes, strains of E. coli deficient in superoxide dismutase and (or) hydroperoxidase were constructed by generalized transduction and their physiological responses to oxygen and oxidant stress examined. Superoxide dismutase was found to be more important than hydroperoxidase in preventing oxygen-dependent growth inhibition and mutagenesis, and in reducing sensitivity to redox-active compounds known to generate the superoxide anion. However, both types of enzymes were required for an effective defense against chemical oxidants that generate superoxide radicals and hydrogen peroxide.
33
Atakan, Muhammed Mustafa, Yanchun Li, Şükran Nazan Koşar, Hüseyin Hüsrev Turnagöl e Xu Yan. "Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective". International Journal of Environmental Research and Public Health 18, n. 13 (5 luglio 2021): 7201. http://dx.doi.org/10.3390/ijerph18137201.
Testo completoAbstract (sommario):
Engaging in regular exercise results in a range of physiological adaptations offering benefits for exercise capacity and health, independent of age, gender or the presence of chronic diseases. Accumulating evidence shows that lack of time is a major impediment to exercise, causing physical inactivity worldwide. This issue has resulted in momentum for interval training models known to elicit higher enjoyment and induce adaptations similar to or greater than moderate-intensity continuous training, despite a lower total exercise volume. Although there is no universal definition, high-intensity interval exercise is characterized by repeated short bursts of intense activity, performed with a “near maximal” or “all-out” effort corresponding to ≥90% of maximal oxygen uptake or >75% of maximal power, with periods of rest or low-intensity exercise. Research has indicated that high-intensity interval training induces numerous physiological adaptations that improve exercise capacity (maximal oxygen uptake, aerobic endurance, anaerobic capacity etc.) and metabolic health in both clinical and healthy (athletes, active and inactive individuals without any apparent disease or disorder) populations. In this paper, a brief history of high-intensity interval training is presented, based on the novel findings of some selected studies on exercise capacity and health, starting from the early 1920s to date. Further, an overview of the mechanisms underlying the physiological adaptations in response to high-intensity interval training is provided.
34
Heinonen, Ilkka, Kari K. Kalliokoski, Jarna C. Hannukainen, Dirk J. Duncker, Pirjo Nuutila e Juhani Knuuti. "Organ-Specific Physiological Responses to Acute Physical Exercise and Long-Term Training in Humans". Physiology 29, n. 6 (novembre 2014): 421–36. http://dx.doi.org/10.1152/physiol.00067.2013.
Testo completoAbstract (sommario):
Virtually all tissues in the human body rely on aerobic metabolism for energy production and are therefore critically dependent on continuous supply of oxygen. Oxygen is provided by blood flow, and, in essence, changes in organ perfusion are also closely associated with alterations in tissue metabolism. In response to acute exercise, blood flow is markedly increased in contracting skeletal muscles and myocardium, but perfusion in other organs (brain and bone) is only slightly enhanced or is even reduced (visceral organs). Despite largely unchanged metabolism and perfusion, repeated exposures to altered hemodynamics and hormonal milieu produced by acute exercise, long-term exercise training appears to be capable of inducing effects also in tissues other than muscles that may yield health benefits. However, the physiological adaptations and driving-force mechanisms in organs such as brain, liver, pancreas, gut, bone, and adipose tissue, remain largely obscure in humans. Along these lines, this review integrates current information on physiological responses to acute exercise and to long-term physical training in major metabolically active human organs. Knowledge is mostly provided based on the state-of-the-art, noninvasive human imaging studies, and directions for future novel research are proposed throughout the review.
35
Fenjan, Haider Mizher, e Khalida Mohammed Khudur. "Application of Active Cycle of Breathing Technique for Patient with Corona Virus at Respiratory Isolation Unit: An Interventional Study". Pakistan Journal of Medical and Health Sciences 16, n. 4 (26 aprile 2022): 825–29. http://dx.doi.org/10.53350/pjmhs22164825.
Testo completoAbstract (sommario):
Background: Active Cycle Breathing Techniques is a technique of breathing exercises that contributes as a rehabilitative lung therapy, and helps to improve readings of body physiological variables such as oxygen saturation rate, heart rate, respiratory rate and Burke scale. Aims: The current study aims to assess the effect of the active course of breathing techniques on patients with coronavirus in the respiratory isolation unit, evaluate the educational program of the active course of breathing techniques on patients with coronavirus in the respiratory isolation unit, in addition to finding the relationship between the effect of active courses of breathing technology on patients with coronavirus. And their social demographic characteristics represented by age, gender, educational level, marital status, occupational status, and area of residence. Methodology: The design of one group pre-test and post-test, the study was conducted on a non-probability-objective sample consisting of forty patients infected with Corona virus in Yousef Hospital for Isolation in Al-Muthanna Governorate. The statistical methods that were applied using the statistical package for social sciences were adopted, Version 26.0. Results: The results indicated that the ACBTs achieved a significant improvement in the patients' parameters, and the educational program significantly improved the knowledge and practices of ACBTs at (0.05˂P) after 5 days of the intervention. Conclusion: Active breathing exercise is effective in improving respiratory parameters, especially the effect on oxygen saturation (spo2), heart rate, respiratory rate, and Borg scale (measurement of dyspnea) among coronavirus patients. It helps mobilize the secretions and helps re-expand lung tissue. On the other hand, the research contributed to providing an educational program that strengthened and enriched the knowledge and practices of patients in benefiting from this technology at the level of health care and in their daily lives. Recommendations: It is recommended to use the active cycle of breathing techniques at least once or more, depending on the patient’s condition, with an emphasis on the use of this technique in addition to other physiotherapy techniques. To teach patients about the active course of breathing techniques to improve their knowledge and practice. Key words: active cycle of breathing techniques(ACBTs) ,COVID-19 patients, respiratory isolation unit, interventional study.
36
Puntarulo, Susana. "Effect of oxidative stress during imbibition of soybean embryonic axes". Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences 102 (1994): 279–86. http://dx.doi.org/10.1017/s026972700001424x.
Testo completoAbstract (sommario):
SynopsisBoth respiration and generation by soybean embryonic axes showed a sharp increase upon germination, leading to a significant increase in the steady-state concentration of and H2O2 after 6 h of imbibition. An assay was developed to assess in vivo generation of reactive oxygen species, based upon DCFH-DA oxidation. Fluorescence of the external medium was dependent on reaction time and axes number and was inhibited by catalase.α-Tocopherol content declined significantly after 24 h of incubation, as compared to the content at the onset of germination. Incubation in the presence of redox cycling agent paraquat (4 mM) for 24 h increased α-tocopherol content to 1.9±0.2 nmol per axis from 1.0 ± 0.1 nmol per axis in the absence of paraquat. Supplementation of the incubation medium with 500 μM Fe-EDTA increased α-tocopherol content to 1.8±0.1 nmol/axis and DCFH-DA oxidation by two-fold.The data presented here showed that active metabolism at the onset of germination increased steady-state concentration of oxygen active species and suggest that cellular content of α-tocopherol is physiologically adjusted as a response to conditions of oxidative stress.
37
Zhao, Rui, Qing-wang Li, Jian Li e Tao Zhang. "Protective effect of Lycium barbarum polysaccharide 4 on kidneys in streptozotocin-induced diabetic rats". Canadian Journal of Physiology and Pharmacology 87, n. 9 (settembre 2009): 711–19. http://dx.doi.org/10.1139/y09-068.
Testo completoAbstract (sommario):
Lycium barbarum polysaccharide (LBP) has been shown to have hypoglycemic and antioxidative properties, although its mode of action is yet unknown. Because oxidative stress is implicated in the pathogenesis of diabetic nephropathy, we evaluated the protective effect of LBP-4, the major active component of Lycium barbarum, on the defensive antioxidative mechanism in kidneys in a streptozotocin-induced diabetic rat model. Moreover, we investigated the effects of LBP-4 on the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in isolated mesangial cells. The role of protein kinase C (PKC)-dependent and -independent pathways in LBP-4-reduced ERK1/2 was studied by bisindolylmaleimide (BIM) IV, an inhibitor of PKC. Diabetic rats treated with LBP-4 (10 mg/kg) for 8 weeks showed increased activity of antioxidant enzymes and increased scavenging of oxygen radicals, while the activity of PKC in the renal cortex was maintained at a physiological level. The decreased activation of ERK1/2 in mesangial cells, through the involvement of PKC, could explain the protective mechanism in kidneys of diabetic rats treated with LBP-4.
38
Spicer, John I., e Simon A. Morley. "Will giant polar amphipods be first to fare badly in an oxygen-poor ocean? Testing hypotheses linking oxygen to body size". Philosophical Transactions of the Royal Society B: Biological Sciences 374, n. 1778 (17 giugno 2019): 20190034. http://dx.doi.org/10.1098/rstb.2019.0034.
Testo completoAbstract (sommario):
It has been suggested that giant Antarctic marine invertebrates will be particularly vulnerable to declining O 2 levels as our ocean warms in line with current climate change predictions. Our study provides some support for this oxygen limitation hypothesis, with larger body sizes being generally more sensitive to O 2 reductions than smaller body sizes. However, it also suggests that the overall picture is a little more complex. We tested predictions from three different, but overlapping, O 2 -related hypotheses accounting for gigantism, using four Antarctic amphipod species encompassing a wide range of body sizes. We found a significant effect of body size, but also of species, in their respiratory responses to acutely declining O 2 tensions. The more active lifestyle of intermediate-sized Prostebbingia brevicornis was supported by a better respiratory performance than predicted by the oxygen limitation hypothesis alone, but consistent with the symmorphosis hypothesis. We suggest that giant polar amphipods are likely to be some of the first to fare badly in an O 2 -poor ocean. However, the products of past evolutionary innovation, such as respiratory pigments that enhance O 2 -transport and novel gas exchange structures, may in some species offset any respiratory disadvantages of either large or small body size. This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.
39
Zhukova, Evgeniya S., Anna Yu Kashina e Anastasiya M. Irkaeva. "Modern aspects of professional cancer treatment: prospects for the use of medical ozone in the correction of free radical homeostasis". Russian Journal of Occupational Health and Industrial Ecology 60, n. 11 (3 dicembre 2020): 767–70. http://dx.doi.org/10.31089/1026-9428-2020-60-11-767-770.
Testo completoAbstract (sommario):
Introduction. The well-known features of oncogenesis make it possible to assume the prospects of medical ozone as part of a comprehensive health-saving therapy for professional oncopathologies. Due to the risk of stimulating the proliferation of tumor cells, research on the search for optimal modes of ozone exposure is relevant. The aim of the study was to evaluate the possibility of using ozonated saline solution (OSS) as part of complex antitumor therapy in an experiment. Materials and methods. The effect of OSS with different concentrations of ozone in the ozone-oxygen mixture on the content of hemoglobin, active products of thiobarbituric acid (TBA) of lipid peroxidation (LP), the degree of oxidative modification of proteins, and the activity of superoxide dismutase and catalase in blood, liver, spleen, and tumor tissues was studied in Mature rats with normal and transplanted cholangiocellular carcinoma. Results. The course effect of the OSS did not have statistically significant changes in the studied biochemical parameters under the conditions of the physiological norm in the experiment. Exposure to OSS during oncogenesis led to a decrease in the content of TBA-active LP products in the liver by more than 30%. Conclusions. Course exposure to OSS with an ozone concentration in an ozone-oxygen mixture of 400 micrograms/l may be promising for the correction of free radical homeostasis as part of complex antitumor therapy, including in oncogenesis due to occupational factors.
40
Kliszczewicz, Brian, Michael McKenzie e Brett Nickerson. "Physiological adaptation following four-weeks of high-intensity functional training". Vojnosanitetski pregled 76, n. 3 (2019): 272–77. http://dx.doi.org/10.2298/vsp170228095k.
Testo completoAbstract (sommario):
Background/Aim. High-Intensity Functional Training (HIFT) is a popular mixed-modal program that utilizes both resistance and aerobic based exercises. The aim of this study was to examine the physiological effects of the HIFT programing on physically active men (10) and women (10) over a four-week period through the measure of the aerobic capacity, anaerobic capacity, and maximal weight lifted. Methods. The participants first completed a maximal oxygen consumption (VO2max) test. After 48-hours of rest, the subjects completed the anaerobic capacity test via the Wingate protocol. Following the Wingate test, the subjects performed a 1-repetition maximum test for squat, snatch and clean at the offsite training location. After the pre-measurements were obtained, the subjects entered a four-week the HIFT intervention and returned to the lab for all post-measurements. Results. Significant improvements were observed in male and female: VO2 max (Pre: 46.7 ? 2.6, 33.7 ? 1.7 mL/kg/min; Post: 49.0 ? 3.0, 35.0 ? 1.8 mL/kg/min), Peak Wingate Power (Pre: 1206 ? 106, 708 ? 44 W; Post: 1283 ? 88, 809 ? 38 W) Mean Wingate Power (Pre: 680 ? 46, 704 ? 48 W; Post: 434 ? 15, 458 ? 18 W; p < 0.05), back squat (Pre: 128.8 ? 8.8 kg, 44.1 ? 6.8 kg; Post: 142.7 ? 9.8, 54.3 ? 6.2 kg) clean (Pre: 82.5 ? 6.2, 24.1 ? 3.4 kg; Post: 92.7 ? 5.8, 33.2 ? 3.3 kg) and snatch (Pre: 59.3 ? 4.4, 20.9 ? 1.7 kg; Post: 69.1 ? 5.3, 25.0 ? 2.3 kg; p < 0.05), respectively. No gender influence on interaction was observed over time (p > 0.05). Conclusion. The HIFT demonstrated the rapid physiological improvements in strength, aerobic and the anaerobic capacity following a four-week intervention in the physically active participants.
41
Zhao, Yuxuan, Min Zhang, Xue Jiang, Shuang Hao, Junru Hu, Jiale Li e Xiaoyang Gai. "The effects of different storage temperatures combined with heat treatment on cucumber’s quality and physiological and biochemical indexes". Trends in Horticulture 5, n. 1 (5 gennaio 2022): 9. http://dx.doi.org/10.24294/th.v5i1.1812.
Testo completoAbstract (sommario):
The effects of different storage temperatures (2, 4 and 8 ℃) and their corresponding optimal heat treatment conditions on the quality, physiological and biochemical indexes of Cucumber Fruits during storage were studied by using the quadratic regression orthogonal rotation combination design. The effects of different storage temperatures (2, 4 and 8 ℃) and their corresponding optimal heat treatment conditions on the chilling injury, hardness, weightlessness rate, polyphenol oxidase (PPO), catalase (CAT), peroxidase (POD), H2O2, super oxygen anion free radical (O2-), ASA and GSH were determined. The results showed that heat treatment could inhibit chilling injury, while heat treatment combined with 4 ℃ low temperature storage could effectively inhibit the decline of fruit hardness and weight loss rate, delay the increase of peroxidase (POD) and polyphenol oxidase (PPO) activities, inhibit the increase of H2O2 and superoxide anion free radical O2- and significantly inhibit the browning of cucumber, delay the decline of ascorbic acid and maintain the content of GSH, it was beneficial to adjust the balance of active oxygen system. The results showed that under the storage condition of 4 ℃, the hot water treatment condition of cucumber was 39.4 ℃ and 24.3 min, which could delay the senescence of cucumber fruit and better maintain the quality of cucumber fruit.
42
Mottola, Michelle F., Stuart Inglis, Chantale R. Brun e Jo-Anne Hammond. "Physiological and metabolic responses of late pregnant women to 40 min of steady-state exercise followed by an oral glucose tolerance perturbation". Journal of Applied Physiology 115, n. 5 (1 settembre 2013): 597–604. http://dx.doi.org/10.1152/japplphysiol.00487.2013.
Testo completoAbstract (sommario):
We examined the physiological and metabolic responses of 24 active late pregnant women to 40 min of vigorous (95% ventilatory threshold) steady-state treadmill exercise followed by a metabolic perturbation [oral glucose tolerance test (OGTT), 75 g] after exercise. Heart rate and respiratory measures were taken throughout exercise, and blood samples were collected during exercise and every 30 min during the 2-h OGTT. Values were compared with those for a group of physically active nonpregnant women ( n = 16) in the luteal phase of the menstrual cycle. Although late pregnant women were heavier, they performed the same work rate (182 vs. 208 W, P > 0.05), with the same oxygen pulse, but responded to the exercise with a blunted heart rate and relative oxygen consumption, with less carbon dioxide expired, possibly due to pregnancy-related adaptations in heart efficiency. Resting glucose concentrations were the same between groups, but by 40 min of exercise (3.8 ± 0.1 vs. 4.6 ± 0.1 mmol/l) and into 15 min of recovery (4.3 ± 0.2 vs. 5.0 ± 0.1 mmol/l), glucose concentrations were diminished in late pregnant women ( P ≤ 0.05, respectively). The pregnancy-induced delay of glucose uptake was seen in response to the postexercise OGTT compared with the nonpregnant women, but insulin sensitivity (ISI) remained (7.4 ± 0.9 vs. 9.7 ± 1.4 ISI, P > 0.05, respectively), with the preservation of the sensitivity of lipolysis inhibition of nonesterified free fatty acids to insulin. These adaptations may be fetoprotective, because our research suggests that 40 min of continuous treadmill exercise is well tolerated by physically active pregnant women. No adverse effects on birth outcome (3.53 ± 0.08 kg birth weight; 39.6 ± 0.33 wk gestational age) were observed.
43
Aldsworth, Timothy G., Rachel L. Sharman, Christine E. R. Dodd e Gordon S. A. B. Stewart. "A Competitive Microflora Increases the Resistance of Salmonella typhimurium to Inimical Processes: Evidence for a Suicide Response". Applied and Environmental Microbiology 64, n. 4 (1 aprile 1998): 1323–27. http://dx.doi.org/10.1128/aem.64.4.1323-1327.1998.
Testo completoAbstract (sommario):
ABSTRACT The presence of a viable competitive microflora at cell densities of 108 CFU ml−1 protects an underlying population of 105 CFU of Salmonella typhimuriumml−1 against freeze injury. The mechanism of enhanced resistance was initially postulated to be via an RpoS-mediated adaptive response. By using an spvRA::luxCDABEreporter we have shown that although the onset of RpoS-mediated gene expression was brought forward by the addition of a competitive microflora, the time taken for induction was measured in hours. Since the protective effect of a competitive microflora is essentially instantaneous, the stationary-phase adaptive response is excluded as the physiological mechanism. The only instantaneous effect of the competitive microflora was a reduction in the percent saturation of oxygen from 100% to less than 10%. For both mild heat treatment (55°C) and freeze injury this change in oxygen tension affordsSalmonella a substantive (2 orders of magnitude) enhancement in survival. By reducing the levels of dissolved oxygen through active respiration, a competitive microflora reduces oxidative damage to exponential-phase cells irrespective of the inimical treatment. These results have led us to propose a suicide hypothesis for the destruction of rapidly growing cells by inimical processes. In essence, the suicide hypothesis proposes that a mild inimical process leads to the growth arrest of exponential-phase cells and to the decoupling of anabolic and catabolic metabolism. The result of this is a free radical burst which is lethal to unadapted cells.
44
Pal, Rameswar, Som Nath Singh, Kaushik Halder, Omveer Singh Tomer, Awadh Bihari Mishra e Mantu Saha. "Effects of Yogic Practice on Metabolism and Antioxidant–Redox Status of Physically Active Males". Journal of Physical Activity and Health 12, n. 4 (aprile 2015): 579–87. http://dx.doi.org/10.1123/jpah.2013-0059.
Testo completoAbstract (sommario):
Background:This study was conducted to evaluate the effects of yogic practice on resting metabolism and redox status.Methods:The study was conducted on 64 physically trained male volunteers selected randomly at the Air Force Academy. The yoga group (n = 34) practiced yogasana, pranayama, and meditation for 3 months (February–May 2011) and the control group (n = 30) performed physical training. Antioxidant variables in blood samples along with physiological parameters were estimated before and after 3 months.Results:No significant difference was noted between baseline data of the control group and yoga group. Reduced glutathione, vitamin C, and vitamin E; the ratio of reduced to oxidized glutathione; and total antioxidant status were increased significantly following yogic practice. Activities of superoxide dismutase, glutathione S-transferase, and glutathione reductase were significantly increased, whereas activity of glutathione peroxidase was significantly decreased following yogic practice. Oxidized glutathione decreased significantly following yogic practice. A nonsignificant decrease of hydroperoxides, protein carbonyl, malondialdehyde, and blood sugar was noted in the yoga group. Carbon dioxide elimination and peripheral oxygen saturation increased significantly following yogic practice. No significant changes were observed in the control group following 3 months of physical training.Conclusions:Regular yogic practice can improve resting metabolism and redox status of the practitioner.
45
Silberstein, L., B. Z. Siegel, S. M. Siegel, A. Mukhtar e M. Galun. "Comparative Studies on Xanthoria Parietina, a Pollution Resistant Lichen, and Ramalina Duriaei, a Sensitive Species. II. Evaluation of Possible Air Pollution-Protection Mechanisms". Lichenologist 28, n. 4 (luglio 1996): 367–83. http://dx.doi.org/10.1006/lich.1996.0034.
Testo completoAbstract (sommario):
AbstractSurveys of the distribution of the lichens Xanthoria panetina and Ramalina duriaei in Israel showed that environments with air pollution had no damaging effectson X. panetina, whereas R. duriaei had disappeared from polluted environments: physiological studies supported this relative sensitivity. Investigations of possible defence mechanisms protecting X. parietina from the damaging effects of air pollution showed a multitude of possible protective systems. These included constitutive avoidance such as: efficient buffering capacity; a relatively high potassium content; and antioxidation by parietin, and induced tolerance such as: SO2 oxidation to non-toxic sulphate; increased glutathione content; induced praline and arginine synthesis; and increased detoxification of active oxygen forms.
46
Atiakshin, Dmitry A., Victoria Shishkina, Dmitry I. Esaulenko, Evgeniy S. Ovsyannikov, Lyubov N. Antakova, Olga A. Gerasimova, Tatiana V. Samoilenko, Pavel Yu Andreev, Sara T. Magerramova e Sofia A. Budnevskaya. "Mast Cells as the Target of the Biological Effects of Molecular Hydrogen in the Specific Tissue Microenvironment". International Journal of Biomedicine 12, n. 2 (5 giugno 2022): 183–87. http://dx.doi.org/10.21103/article12(2)_ra2.
Testo completoAbstract (sommario):
Mast cells (MCs) as key players in the development of both physiological and pathological processes in the organism can form a specific tissue microenvironment. Having a rich secretion of biologically active substances, MCs can secrete tryptase and/or chymase and thereby participate in the regulation of processes such as inflammation, neoangiogenesis, allergic reactions, and oncogenesis. Reactive oxygen intermediates (ROI) play an essential role in regulation of MC degranulation, shown in vitro and in vivo models. Application of molecular hydrogen as a substance with antioxidant characteristics pathogenically appears to be an important mechanism decreasing MC secretory activity, and, as a consequence, a novel option to reduce an inflammatory background in the specific tissue microenvironment.
47
Lerchundi, Rodrigo, Ignacio Fernández-Moncada, Yasna Contreras-Baeza, Tamara Sotelo-Hitschfeld, Philipp Mächler, Matthias T. Wyss, Jillian Stobart et al. "NH4+ triggers the release of astrocytic lactate via mitochondrial pyruvate shunting". Proceedings of the National Academy of Sciences 112, n. 35 (18 agosto 2015): 11090–95. http://dx.doi.org/10.1073/pnas.1508259112.
Testo completoAbstract (sommario):
Neural activity is accompanied by a transient mismatch between local glucose and oxygen metabolism, a phenomenon of physiological and pathophysiological importance termed aerobic glycolysis. Previous studies have proposed glutamate and K+ as the neuronal signals that trigger aerobic glycolysis in astrocytes. Here we used a panel of genetically encoded FRET sensors in vitro and in vivo to investigate the participation of NH4+, a by-product of catabolism that is also released by active neurons. Astrocytes in mixed cortical cultures responded to physiological levels of NH4+ with an acute rise in cytosolic lactate followed by lactate release into the extracellular space, as detected by a lactate-sniffer. An acute increase in astrocytic lactate was also observed in acute hippocampal slices exposed to NH4+ and in the somatosensory cortex of anesthetized mice in response to i.v. NH4+. Unexpectedly, NH4+ had no effect on astrocytic glucose consumption. Parallel measurements showed simultaneous cytosolic pyruvate accumulation and NADH depletion, suggesting the involvement of mitochondria. An inhibitor-stop technique confirmed a strong inhibition of mitochondrial pyruvate uptake that can be explained by mitochondrial matrix acidification. These results show that physiological NH4+ diverts the flux of pyruvate from mitochondria to lactate production and release. Considering that NH4+ is produced stoichiometrically with glutamate during excitatory neurotransmission, we propose that NH4+ behaves as an intercellular signal and that pyruvate shunting contributes to aerobic lactate production by astrocytes.
48
Kim, Young-Woong, e Tatiana V. Byzova. "Oxidative stress in angiogenesis and vascular disease". Blood 123, n. 5 (30 gennaio 2014): 625–31. http://dx.doi.org/10.1182/blood-2013-09-512749.
Testo completoAbstract (sommario):
Abstract Despite the damaging effect on tissues at a high concentration, it has been gradually established that oxidative stress plays a positive role during angiogenesis. In adults, physiological or pathological angiogenesis is initiated by tissue demands for oxygen and nutrients, resulting in a hypoxia/reoxygenation cycle, which, in turn promotes the formation of reactive oxygen species (ROS). The ROS can be generated either endogenously, through mitochondrial electron transport chain reactions and nicotinamide adenine dinucleotide phosphate oxidase, or exogenously, resulting from exposure to environmental agents, such as ultraviolet or ionizing radiation. In many conditions, ROS promotes angiogenesis, either directly or via the generation of active oxidation products, including peroxidized lipids. The latter lipid metabolites are generated in excess during atherosclerosis, thereby linking atherogenic processes and pathological angiogenesis. Although the main mechanism of oxidative stress-induced angiogenesis involves hypoxia-inducible factor/vascular endothelial growth factor (VEGF) signaling, recent studies have identified several pathways that are VEGF-independent. This review aims to provide a summary of the past and present views on the role of oxidative stress as a mediator and modulator of angiogenesis, and to highlight newly identified mechanisms.
49
Shinzawa-Itoh, Kyoko, Takashi Sugimura, Tomonori Misaki, Yoshiki Tadehara, Shogo Yamamoto, Makoto Hanada, Naomine Yano et al. "Monomeric structure of an active form of bovine cytochrome c oxidase". Proceedings of the National Academy of Sciences 116, n. 40 (18 settembre 2019): 19945–51. http://dx.doi.org/10.1073/pnas.1907183116.
Testo completoAbstract (sommario):
Cytochrome c oxidase (CcO), a membrane enzyme in the respiratory chain, catalyzes oxygen reduction by coupling electron and proton transfer through the enzyme with a proton pump across the membrane. In all crystals reported to date, bovine CcO exists as a dimer with the same intermonomer contacts, whereas CcOs and related enzymes from prokaryotes exist as monomers. Recent structural analyses of the mitochondrial respiratory supercomplex revealed that CcO monomer associates with complex I and complex III, indicating that the monomeric state is functionally important. In this study, we prepared monomeric and dimeric bovine CcO, stabilized using amphipol, and showed that the monomer had high activity. In addition, using a newly synthesized detergent, we determined the oxidized and reduced structures of monomer with resolutions of 1.85 and 1.95 Å, respectively. Structural comparison of the monomer and dimer revealed that a hydrogen bond network of water molecules is formed at the entry surface of the proton transfer pathway, termed the K-pathway, in monomeric CcO, whereas this network is altered in dimeric CcO. Based on these results, we propose that the monomer is the activated form, whereas the dimer can be regarded as a physiological standby form in the mitochondrial membrane. We also determined phospholipid structures based on electron density together with the anomalous scattering effect of phosphorus atoms. Two cardiolipins are found at the interface region of the supercomplex. We discuss formation of the monomeric CcO, dimeric CcO, and supercomplex, as well as their role in regulation of CcO activity.
50
Navalta, James Wilfred, Brian Keith McFarlin, Thomas Scott Lyons, John Clifton Faircloth, Nicholas T. Bacon e Zachary J. Callahan. "Exercise-induced lymphocyte apoptosis attributable to cycle ergometer exercise in endurance-trained individuals". Applied Physiology, Nutrition, and Metabolism 34, n. 4 (agosto 2009): 603–8. http://dx.doi.org/10.1139/h09-018.
Testo completoAbstract (sommario):
Exercise as a stimulus to induce lymphocyte apoptosis remains controversial. Differences may be due to participant fitness level or the methodology of assessing cell death. Another important issue is the mode of exercise used to induce physiological changes. Treadmill exercise typically induces significant apoptosis in human lymphocytes; however, the effect of cycle exercise is less clear. The 2 main purposes of this study were to assess if cycle ergometer exercise induces similar changes in apoptosis, and to further characterize the morphological method of assessing cell death. Endurance athletes (n = 10; peak oxygen consumption = 55.1 mL·kg–1·min–1) completed a 60-min ride on a cycle ergometer at ~80% peak oxygen consumption. Blood samples taken before (PRE) and after (POST) exercise were used to make blood films for apoptotic analysis via the morphological technique. A significant increase was observed in the apoptotic index following cycle exercise (PRE = 7.3 ± 2%, POST = 12.9 ± 2%; p < 0.01). On average, it took 42 ± 9 min to read PRE sample slides, which was significantly longer than the 27 ± 4 min needed for POST slides (p < 0.01). To our knowledge, this study is the first to report that exercise on the cycle ergometer produces changes in lymphocyte apoptosis. The values measured during this study were about 20% lower than those we have observed following treadmill running, which may be explained by differences in active muscle mass and the resultant physiological stress between the 2 exercise modes. It is likely that cycling may result in reduced immunosuppression, compared with running at the same intensity.