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1.
Nutr Health ; 29(1): 107-114, 2023 Mar.
Article in English | MEDLINE | ID: mdl-34931931

ABSTRACT

Background: To detect longitudinal changes of resting metabolic rate (RMR) resulting from the effects of energetic stress, reliable RMR measurements are crucial. The Vyntus CPX is a new automated indirect calorimetry system for which RMR reliability has not been determined. Additionally, its agreement with common predictive RMR formulas is unknown. Aim: To determine the within and between-day reliability of RMR measurements using the Vyntus CPX system and its agreement with predictive RMR formulas. Methods: Young (31 ± 7 years) healthy participants (n = 26, 12 females, 14 males) completed three measurements of RMR, two consecutive measures on the same day, one the day before/after, all under standardised conditions. Reliability was assessed with pairwise comparisons of between-day at the same time (BDST), within day consecutive measurements (WDCM) and between-day different time (BDDT), for parameters of reliability (mean change (MC), intraclass correlation (ICC) and typical error of measurement (TEM)). Measured RMR values (kcal/day) were compared against predictive values of 4 common formulas. Results: Parameters of reliability (mean, (95% confidence interval)) were: -BDST: MC, 0.2(-2.3-2.7)% (p = 0.67); ICC, 0.92(0.84-0.97); TEM, 4.5(3.5-6.2)%. -WDCM: MC, -2.5(-6.2-1.3)% (p = 0.21); ICC, 0.88(0.74-0.88); TEM, 7.0(5.4-9.8)%. -BDDT: MC, -1.5(-4.8-1.9)% (p = 0.57); ICC, 0.90(0.76-0.95); TEM, 6.1(4.8-8.5)%. RMRratios (measured/predicted) were: 1.04 ± 0.14 (Nelson, p = 0.13), 1.03 ± 0.10 (Mifflin, p = 0.21), 0.98 ± 0.09 (Harris-benedict, p = 0.30), 0.95 ± 0.11 (Cunningham1980, p = 0.01), 1.00 ± 0.12 (Cunningham1991, p = 0.90) and 0.96 ± 0.13 (DXA, p = 0.03). Conclusions: The Vyntus CPX is reliable and measured RMR values agreed with four predictive formulas but are lower than Cunningham1980 and DXA RMR estimates for this population.


Subject(s)
Basal Metabolism , Male , Female , Humans , Reproducibility of Results , Calorimetry, Indirect/methods , Healthy Volunteers
2.
Neumol. pediátr. (En línea) ; 15(2): 339-345, mayo 2020. tab, ilus
Article in Spanish | LILACS | ID: biblio-1099680

ABSTRACT

The appearance of a new nosological entity named by the World Health Organization (WHO) as CoVID-19, which is causing a global pandemic, has meant a major medical challenge. This article tries to concentrate the most important aspects in the management pediatric of the severe CoVID-19 patient, reviewing the existing literature with emphasis on ventilatory, hemodynamic and other affected systems management. It must be taken into account that due to the high possibility of contagion, it is necessary to review the protection measures for health personnel in the procedures that are routine in the seriously ill patient.


La aparición de una nueva entidad nosológica denominada por la Organización Mundial de la Salud (OMS) como CoVID-19, está causando una pandemia mundial que ha significado un desafío médico de gran envergadura Este artículo trata de concentrar los aspectos más importantes en el manejo pediátrico del paciente CoVID-19 grave, revisando la literatura existente poniendo énfasis en el manejo ventilatorio, hemodinámico y de otros sistemas afectados. Hay que tomar en cuenta que debido a la alta posibilidad de contagio se hace necesario revisar las medidas de protección para el personal de salud en los procedimientos que son de rutina en el paciente gravemente enfermo.


Subject(s)
Humans , Child , Pneumonia, Viral/therapy , Intensive Care Units, Pediatric , Coronavirus Infections/therapy , Betacoronavirus , Oxygen Inhalation Therapy , Pneumonia, Viral/complications , Respiration, Artificial/methods , Coronavirus Infections/complications , Critical Care , Pandemics
3.
J Nutr Health Aging ; 23(1): 42-50, 2019.
Article in English | MEDLINE | ID: mdl-30569067

ABSTRACT

OBJECTIVE: Elderly muscle seems less sensitive to the anabolic stimulus of a meal. Changes in blood concentrations of leucine are suggested as one important trigger of the anabolic response in muscle. The aim of this study was to investigate whether native whey protein, containing high amounts of leucine, may be a more potent stimulator of muscle protein synthesis (MPS) in elderly than regular whey protein (WPC-80) or milk. DESIGN: Randomized controlled partial crossover. SETTING: Norwegian School of Sport Sciences. PARTICIPANTS: 21 healthy elderly men and women (≥70 years). INTERVENTION: Participants received either 20 g of WPC-80 and native whey (n = 11) on separate days in a crossover design, or milk (n = 10). Supplements were ingested immediately and two hours after a bout of lower body heavy-load resistance exercise. MEASUREMENTS: Blood samples and muscle biopsies were collected to measure blood concentrations of amino acids by gas-chromatography mass spectrometry (GCMS), phosphorylation of p70S6K, 4E-BP1 and eEF-2 by immunoblotting and mixed muscle fractional synthetic rate (FSR) by use of [2H5]phenylalanine-infusion, GCMS and isotope-ratio mass spectrometry. RESULTS: Native whey increased blood leucine concentrations more than WPC-80 (P < 0.05), but not p70S6K phosphorylation or mixed muscle FSR. Both whey supplements increased blood leucine concentrations (P < 0.01) and P70S6K phosphorylation more than milk (P = 0.014). Native whey reached higher mixed muscle FSR values than milk (P = 0.026) 1-3h after exercise. CONCLUSIONS: Despite greater increases in blood leucine concentrations than WPC-80 and milk, native whey was only superior to milk concerning increases in MPS and phosphorylation of P70S6K during a 5-hour post-exercise period in elderly individuals.


Subject(s)
Dietary Supplements/analysis , Exercise/physiology , Leucine/metabolism , Muscle Proteins/physiology , Whey Proteins/metabolism , Whey/metabolism , Aged , Animals , Cross-Over Studies , Female , Humans , Male
4.
Scand J Med Sci Sports ; 28(9): 1982-1995, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29749641

ABSTRACT

High doses of isolated antioxidant supplements such as vitamin C and E have demonstrated the potential to blunt cellular adaptations to training. It is, however, unknown whether intake of high doses of antioxidants from foods has similar effects. Hence, the aim of the study was to investigate whether intake of antioxidant-rich foods affects adaptations to altitude training in elite athletes. In a randomized controlled trial, 31 national team endurance athletes (23 ± 5 years) ingested antioxidant-rich foods (n = 16) or eucaloric control foods (n = 15) daily during a 3-week altitude training camp (2320 m). Changes from baseline to post-altitude in hemoglobin mass (Hbmass ; optimized CO rebreathing), maximal oxygen uptake (VO2max ; n = 16) or 100 m swimming performance (n = 10), and blood parameters were compared between the groups. The antioxidant group significantly increased total intake of antioxidant-rich foods (~118%) compared to the control group during the intervention. The total study population improved VO2max by 2.5% (1.7 mL/kg/min, P = .006) and Hbmass by 4.7% (48 g, P < .001), but not 100 m swimming performance. No difference was found between the groups regarding changes in Hbmass , VO2max or swimming performance. However, hemoglobin concentration increased more in the antioxidant group (effect size = 0.7; P = .045) with a concomitantly larger decrease in plasma and blood volumes compared to control group. Changes in ferritin and erythropoietin from pre- to post-altitude did not differ between the groups. Doubling the intake of antioxidant-rich foods was well tolerated and did not negatively influence the adaptive response to altitude training in elite endurance athletes.


Subject(s)
Acclimatization , Altitude , Antioxidants/administration & dosage , Athletic Performance/physiology , Sports Nutritional Physiological Phenomena , Adult , Athletes , Diet , Erythropoietin/blood , Female , Food , Hemoglobins/analysis , Humans , Male , Oxygen Consumption , Physical Endurance , Swimming/physiology , Young Adult
5.
Acta Physiol (Oxf) ; 224(1): e13069, 2018 09.
Article in English | MEDLINE | ID: mdl-29608242

ABSTRACT

AIM: Autophagy and unfolded protein response (UPR) appear to be important for skeletal muscle homoeostasis and may be altered by exercise. Our aim was to investigate the effects of resistance exercise and training on indicators of UPR and autophagy in healthy untrained young men (n = 12, 27 ± 4 years) and older men (n = 8, 61 ± 6 years) as well as in resistance-trained individuals (n = 15, 25 ± 5 years). METHODS: Indicators of autophagy and UPR were investigated from the muscle biopsies after a single resistance exercise bout and after 21 weeks of resistance training. RESULTS: Lipidated LC3II as an indicator of autophagosome content increased at 48 hours post-resistance exercise (P < .05) and after a resistance training period (P < .01) in untrained young men but not in older men. Several UPRER markers, typically induced by protein misfolding in endoplasmic reticulum, were increased at 48 hours post-resistance exercise in untrained young and older men (P < .05) but were unaltered after the 21-week resistance training period regardless of age. UPR was unchanged within the first few hours after the resistance exercise bout regardless of the training status. Changes in autophagy and UPRER indicators did not correlate with a resistance training-induced increase in muscle strength and size. CONCLUSION: Autophagosome content is increased by resistance training in young previously untrained men, but this response may be blunted by ageing. However, unfolded protein response is induced by an unaccustomed resistance exercise bout in a delayed manner regardless of age.


Subject(s)
Autophagy , Muscle Contraction , Muscle, Skeletal/pathology , Resistance Training , Unfolded Protein Response , Adult , Age Factors , Aged , Autophagosomes/metabolism , Autophagosomes/pathology , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum/pathology , Humans , Male , Microtubule-Associated Proteins/metabolism , Middle Aged , Muscle Strength , Muscle, Skeletal/metabolism , Oxidative Stress , Sex Factors , Time Factors , Young Adult
6.
Scand J Med Sci Sports ; 28(1): 40-47, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28453868

ABSTRACT

Our primary aim was to study the effects of 24 weeks of combined aerobic and resistance training performed on the same day or on different days on inflammation markers. Physically active, healthy young men were randomly divided into three groups that performed: aerobic and resistance training consecutively in the same training session (SS) 2-3 days wk-1 or on alternating days (AD) 4-6 days wk-1 as well as control (C). The total training volume was matched in the training groups. The control group was asked to maintain their habitual physical activity and exercise level. Maximal leg press strength (1RM) and peak oxygen uptake (VO2peak ) were measured. Abdominal fat mass was estimated with dual-energy absorptiometry (DXA). High-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α), and adipocytokines resistin, adiponectin, and leptin were analyzed from plasma samples. Training significantly reduced circulating hs-CRP, leptin, and resistin in both training groups (P<.05), whereas MCP-1 and TNF-α decreased only in AD (P<.05). Significant correlations were observed between changes in abdominal fat mass and corresponding changes in MCP-1, leptin, adiponectin, and resistin. Long-term combined aerobic and resistance training reduced markers of subclinical inflammation in healthy young men. The results indicate that a higher frequency of individual exercise sessions might be more beneficial with respect to the anti-inflammatory effects of physical activity. The decreases in inflammation markers seem to be related to decreases in abdominal fat mass.


Subject(s)
Exercise , Inflammation/blood , Resistance Training , Abdominal Fat , Adiponectin/blood , Adult , Biomarkers/blood , Body Composition , C-Reactive Protein/analysis , Chemokine CCL2/blood , Humans , Interleukin-6/blood , Leptin/blood , Male , Oxygen Consumption , Resistin/blood , Tumor Necrosis Factor-alpha/blood
7.
Scand J Med Sci Sports ; 28(3): 893-904, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29024041

ABSTRACT

The purpose of this study was to investigate the effects of adding strength training with or without vibration to cross-country (XC) skiers' endurance training on double-poling (DP) performance, physiological, and kinematic adaptations. Twenty-one well-trained male XC-skiers combined endurance- and upper-body strength training three times per week, either with (n = 11) or without (n = 10) superimposed vibrations for 8 weeks, whereas eight skiers performed endurance training only (CON). Testing included 1RM in upper-body exercises, work economy, neural activation, oxygen saturation in muscle, and DP kinematics during a prolonged submaximal DP roller ski test which was directly followed by a time to exhaustion (TTE) test. TTE was also performed in rested state, and the difference between the two TTE tests (TTEdiff ) determined the ability to maintain DP performance after prolonged exercise. Vibration induced no additional effect on strength or endurance gains. Therefore, the two strength training groups were pooled (STR, n = 21). 1RM in STR increased more than in CON (P < .05), and there were no differences in changes between STR and CON in any measurements during prolonged submaximal DP. STR improved TTE following prolonged DP (20 ± 16%, P < .001) and revealed a moderate effect size compared to CON (ES = 0.80; P = .07). Furthermore, STR improved TTEdiff more than CON (P = .049). In conclusion, STR superiorly improved 1RM strength, DP performance following prolonged submaximal DP and TTEdiff , indicating a specific effect of improved strength on the ability to maintain performance after long-lasting exercise.


Subject(s)
Athletic Performance , Resistance Training , Skiing/physiology , Absorptiometry, Photon , Adult , Biomechanical Phenomena , Electromyography , Exercise Test , Humans , Lactic Acid/blood , Male , Muscle Strength , Oxygen Consumption , Physical Conditioning, Human , Spectroscopy, Near-Infrared , Young Adult
8.
BMC Nutr ; 3: 70, 2017.
Article in English | MEDLINE | ID: mdl-32153849

ABSTRACT

BACKGROUND: Supplementation with large doses of antioxidants, such as vitamin C and E, has been shown to blunt some adaptations to endurance training. The effects of antioxidant supplementation on adaptations to strength training is sparsely studied. Herein we investigated the effects of vitamin C and E supplementation on acute stress responses to exercise and adaptation to traditional heavy load strength training. METHODS: In a double blind placebo-controlled design, twenty-eight, young, trained males and females were randomly assigned to receive either vitamin C and E (C: 1000 mg, E: 235 mg, per day) or placebo supplements, and underwent strength training for 10 weeks. After five weeks, a subgroup conducted a strength training session to investigate acute stress responses. Muscle samples were obtained to investigate changes in stress responses and in proteins and mRNA related to the heat shock proteins (HSPs) or antioxidant enzymes. RESULTS: The acute responses to the exercise session revealed activation of the NFκB pathway indicated by degradation of IκBα in both groups. Vitamin C and E supplementation had, however, no effects on the acute stress responses. Furthermore, ten weeks of strength training did not change muscle αB-crystallin, HSP27, HSP70, GPx1 or mnSOD levels, with no influence of supplementation. CONCLUSIONS: Our results showed that although vitamin C and E supplementation has been shown to interfere with training adaptations, it did not affect acute stress responses or long-term training adaptations in the HSPs or antioxidant enzymes in this study.

9.
Transpl Infect Dis ; 18(5): 706-713, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27492796

ABSTRACT

BACKGROUND: Morbidity and mortality related to Clostridium difficile infection (CDI) has increased, but epidemiology and risk factors within pediatric solid organ transplant (SOT) recipients are uncertain. METHODS: A retrospective cohort study of SOT recipients age ≤18 years at transplantation from 2010 to 2013 was performed. Patients with CDI were compared with matched CDI-negative controls with diarrhea. RESULTS: Of 202 patients, the majority were male (58%) and Caucasian (77%). Kidney (42%) was the most common organ transplanted, followed by liver (38%), heart (17%), and multivisceral/intestine (3%). Age ranged from 3 weeks to 18 years (median 4.7 years, mean 6.6; interquartile range [IQR] 1.5-11.2). In 104 SOT recipients, at least 1 unformed stool was tested; 25 patients were positive for CDI. Most testing occurred by 60 days post transplant (mean 164, median 57, IQR 14-227). First negative tests occurred concurrently (mean 153, median 54, IQR 13-214) to the 25 patients with CDI (mean 199, median 65, IQR 32-238). In univariable analyses, age, gender, ethnicity, obesity, and calcineurin inhibitor choice were not associated with CDI. Liver recipients were more likely to have CDI (18.4% liver, 4.7% kidney, 8.8% heart, P < 0.01). Twenty CDI patients were matched to 35 controls. In multivariable analyses, neither recent hospitalization nor antibiotic duration or intensity was associated with CDI. Acid-blockade appeared protective (risk ratio 0.13, 95% confidence interval 0.02-0.78). CONCLUSIONS: CDI occurs in 12% of pediatric SOT recipients, but 24% of those tested with diarrhea were positive. In patients with diarrhea, prior hospitalization and antibiotic duration or intensity were not associated with CDI.


Subject(s)
Clostridioides difficile/isolation & purification , Clostridium Infections/epidemiology , Diarrhea/epidemiology , Feces/microbiology , Organ Transplantation/adverse effects , Adolescent , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Child , Child, Preschool , Clostridium Infections/microbiology , Diarrhea/microbiology , Female , Hospitalization , Humans , Immunosuppression Therapy/adverse effects , Infant , Infant, Newborn , Male , Odds Ratio , Retrospective Studies , Risk Factors
10.
Scand J Med Sci Sports ; 26(7): 755-63, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26129928

ABSTRACT

The aim of this study was to investigate the effects of vitamin C and E supplementation on changes in muscle mass (lean mass and muscle thickness) and strength during 12 weeks of strength training in elderly men. Thirty-four elderly males (60-81 years) were randomized to either an antioxidant group (500 mg of vitamin C and 117.5 mg vitamin E before and after training) or a placebo group following the same strength training program (three sessions per week). Body composition was assessed with dual-energy X-ray absorptiometry and muscle thickness by ultrasound imaging. Muscle strength was measured as one-repetition maximum (1RM). Total lean mass increased by 3.9% (95% confidence intervals: 3.0, 5.2) and 1.4% (0, 5.4) in the placebo and antioxidant groups, respectively, revealing larger gains in the placebo group (P = 0.04). Similarly, the thickness of m. rectus femoris increased more in the placebo group [16.2% (12.8, 24.1)] than in the antioxidant group [10.9% (9.8, 13.5); P = 0.01]. Increases of lean mass in trunk and arms, and muscle thickness of elbow flexors, did not differ significantly between groups. With no group differences, 1RM improved in the range of 15-21% (P < 0.001). In conclusion, high-dosage vitamin C and E supplementation blunted certain muscular adaptations to strength training in elderly men.


Subject(s)
Antioxidants/pharmacology , Ascorbic Acid/pharmacology , Body Composition/drug effects , Quadriceps Muscle/drug effects , Resistance Training , Vitamin E/pharmacology , Absorptiometry, Photon , Aged , Aged, 80 and over , Dietary Supplements , Humans , Male , Middle Aged , Muscle Strength , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/drug effects , Organ Size , Quadriceps Muscle/diagnostic imaging , Ultrasonography
11.
Scand J Med Sci Sports ; 26(6): 659-65, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26031482

ABSTRACT

The purpose of this study was to examine whether athletes with highly flexible hamstring muscle-tendon units display different passive and contractile mechanical properties compared with controls. Flexibility, passive, and active torque-angle properties were assessed in 21 female elite rhythmic gymnasts and 16 female age-matched athletes. Passive resistance to stretch was measured during knee extension with the hip fixed at 100° of flexion. Concentric isokinetic maximal voluntary knee flexion and extension torques were measured at 60°/s in the same position. Tests of flexibility and passive resistance to stretch indicated a greater flexibility in the gymnasts. Despite no differences between groups in knee flexion and extension peak torque, gymnasts reached knee flexion peak torque at more extended positions (longer muscle lengths) and displayed significantly different torque-angle relations. When active torque was corrected for passive resistance to stretch, differences increased, gymnasts producing more work, and maintaining ≥ 70% of peak torque over a larger range of joint excursion. In conclusion, individuals with a higher flexibility of the hamstrings MTU present a different torque-angle profile, favoring the production of flexion torque toward extended knee positions, displaying larger functional range of motion and a higher mechanical work output during knee flexion.


Subject(s)
Gymnastics/physiology , Hamstring Muscles/physiology , Knee Joint/physiology , Range of Motion, Articular/physiology , Tendons/physiology , Adolescent , Biomechanical Phenomena , Ergometry , Female , Humans , Muscle Stretching Exercises , Torque , Young Adult
12.
J Physiol ; 592(24): 5391-408, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-25384788

ABSTRACT

This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day(-1) and 235 mg day(-1), respectively), or a placebo, for 10 weeks. During this period the participants' training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training.


Subject(s)
Ascorbic Acid/pharmacology , MAP Kinase Signaling System , Muscle, Skeletal/metabolism , Resistance Training , Vitamin E/pharmacology , Vitamins/pharmacology , Adaptation, Physiological , Adult , Ascorbic Acid/administration & dosage , Dietary Supplements , Female , Humans , Isometric Contraction , Male , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Muscle Proteins/genetics , Muscle Proteins/metabolism , Muscle, Skeletal/drug effects , Muscle, Skeletal/growth & development , Muscle, Skeletal/physiology , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Vitamin E/administration & dosage , Vitamins/administration & dosage , p38 Mitogen-Activated Protein Kinases/metabolism
13.
Acta Physiol (Oxf) ; 211(4): 634-46, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24762334

ABSTRACT

AIM: Heat-shock proteins (HSP) are important chaperones for stressed and damaged proteins. Low-load blood-flow-restricted resistance exercise (BFRE) is generally believed not to induce significant muscle damage, but is hitherto unverified with intracellular markers. Consequently, the aim of this study was to investigate the HSP response after BFRE in human skeletal muscle. METHODS: Nine healthy volunteers performed five sets to failure of unilateral knee extension at 30% of 1RM with partial blood-flow restriction. The contralateral leg performed the same work with free blood flow. Muscle biopsies were collected before exercise, 1, 24 and 48 h after exercise and analysed for HSP27, αB-crystallin, HSP70, desmin, glycogen content and myosin heavy chain by immunohistochemistry, ELISA and western blotting. RESULTS: One hour after exercise, HSP27 and αB-crystallin levels were reduced in the cytosolic and increased in the cytoskeletal fraction in the BFRE leg. HSP70 showed a delayed response and was increased over 48 h in the BFRE leg. Immunohistochemical analyses showed higher staining intensity of HSP70 in type 1 fibres in the BFRE leg at 24 and 48 h post-exercise. PAS staining showed decreased glycogen levels after BFRE, and interestingly, glycogen was still depleted 48 h after exercise in the same fibres displaying high HSP70 staining (type 1 fibres). CONCLUSION: Translocation of HSP27 and αB-crystallin from cytosol to cytoskeletal structures indicates that cytoskeletal proteins are stressed during BFRE. However, overt signs of myofibrillar disruptions were not observed. Interestingly, the stress response was more pronounced in type 1 than in type 2 fibres and coincided with low glycogen levels.


Subject(s)
HSP27 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/metabolism , Muscle, Skeletal/metabolism , Resistance Training , alpha-Crystallin B Chain/metabolism , Adult , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Female , Heat-Shock Proteins , Humans , Immunohistochemistry , Male , Molecular Chaperones , Protein Transport/physiology , Young Adult
14.
Science ; 343(6169): 1248097, 2014 Jan 24.
Article in English | MEDLINE | ID: mdl-24458648

ABSTRACT

Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe(+3)-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precipitated from fluids that circulated after the Endeavour impact. Compositional data for fractures in the layered rocks suggest formation of Al-rich smectites by aqueous leaching. Evidence is thus preserved for water-rock interactions before and after the impact, with aqueous environments of slightly acidic to circum-neutral pH that would have been more favorable for prebiotic chemistry and microorganisms than those recorded by younger sulfate-rich rocks at Meridiani Planum.


Subject(s)
Exobiology , Extraterrestrial Environment/chemistry , Mars , Water , Bacteria , Geologic Sediments , Hydrogen-Ion Concentration , Silicates/analysis , Silicates/chemistry , Spacecraft , Sulfates/chemistry
15.
Astrobiology ; 13(12): 1166-98, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24303959

ABSTRACT

The future exploration of Mars will require access to the subsurface, along with acquisition of samples for scientific analysis and ground-truthing of water ice and mineral reserves for in situ resource utilization. The Icebreaker drill is an integral part of the Icebreaker mission concept to search for life in ice-rich regions on Mars. Since the mission targets Mars Special Regions as defined by the Committee on Space Research (COSPAR), the drill has to meet the appropriate cleanliness standards as requested by NASA's Planetary Protection Office. In addition, the Icebreaker mission carries life-detection instruments; and in turn, the drill and sample delivery system have to meet stringent contamination requirements to prevent false positives. This paper reports on the development and testing of the Icebreaker drill, a 1 m class rotary-percussive drill and triple redundant sample delivery system. The drill acquires subsurface samples in short, approximately 10 cm bites, which makes the sampling system robust and prevents thawing and phase changes in the target materials. Autonomous drilling, sample acquisition, and sample transfer have been successfully demonstrated in Mars analog environments in the Arctic and the Antarctic Dry Valleys, as well as in a Mars environmental chamber. In all environments, the drill has been shown to perform at the "1-1-100-100" level; that is, it drilled to 1 m depth in approximately 1 hour with less than 100 N weight on bit and approximately 100 W of power. The drilled substrate varied and included pure ice, ice-rich regolith with and without rocks and with and without 2% perchlorate, and whole rocks. The drill is currently at a Technology Readiness Level (TRL) of 5. The next-generation Icebreaker drill weighs 10 kg, which is representative of the flightlike model at TRL 5/6.


Subject(s)
Ice , Mars , Space Flight
16.
Eur J Appl Physiol ; 113(7): 1883-93, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23467900

ABSTRACT

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely consumed in relation to pain and injuries in skeletal muscle, but may adversely affect muscle adaptation probably via inhibition of prostaglandin synthesis. Induction of heat shock proteins (HSP) represents an important adaptive response in muscle subjected to stress, and in several cell types including cardiac myocytes prostaglandins are important in induction of the HSP response. This study aimed to determine the influence of NSAIDs on the HSP response to eccentric exercise in human skeletal muscle. Healthy males performed 200 maximal eccentric contractions with each leg with intramuscular infusion of the NSAID indomethacin or placebo. Biopsies were obtained from m. vastus lateralis before and after (5, 28 hrs and 8 days) the exercise bout from both legs (NSAID vs unblocked leg) and analysed for expression of the HSPs HSP70, HSP27 and αB-crystallin (mRNA and protein). NSAID did not affect the mRNA expression of any of the HSPs. Compared to pre values, the mRNA expression of all HSPs was increased; αB-crystallin, 3.6- and 5.4-fold; HSP70, 26- and 3.4-fold; and HSP27: 4.8- and 6.5-fold at 5 and 28 hrs post-exercise, respectively (all p < 0.008). Immunohistochemical stainings for αB-crystallin and HSP70 revealed increased staining in some samples but with no differences between legs. Changes in force-generating capacity correlated with both αB-crystallin and HSP70 mRNA and immunohistochemisty data. Increased expression of HSPs was observed on mRNA and protein level following eccentric exercise; however, this response was unaffected by local intramuscular infusion of NSAIDs.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Exercise , HSP27 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/metabolism , Indomethacin/pharmacology , Muscle, Skeletal/metabolism , Adult , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Case-Control Studies , HSP27 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/genetics , Humans , Indomethacin/administration & dosage , Infusions, Parenteral , Leg/physiology , Male , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiology , RNA, Messenger/metabolism , Transcription, Genetic/drug effects , alpha-Crystallin B Chain/genetics , alpha-Crystallin B Chain/metabolism
17.
Science ; 336(6081): 570-6, 2012 May 04.
Article in English | MEDLINE | ID: mdl-22556248

ABSTRACT

The rover Opportunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars. Basaltic breccias produced by the impact form the rim deposits, with stratigraphy similar to that observed at similar-sized craters on Earth. Highly localized zinc enrichments in some breccia materials suggest hydrothermal alteration of rim deposits. Gypsum-rich veins cut sedimentary rocks adjacent to the crater rim. The gypsum was precipitated from low-temperature aqueous fluids flowing upward from the ancient materials of the rim, leading temporarily to potentially habitable conditions and providing some of the waters involved in formation of the ubiquitous sulfate-rich sandstones of the Meridiani region.


Subject(s)
Mars , Water , Calcium Sulfate , Extraterrestrial Environment , Geological Phenomena , Meteoroids , Silicates , Spacecraft , Zinc
18.
Eur J Appl Physiol ; 112(5): 1773-82, 2012 May.
Article in English | MEDLINE | ID: mdl-21901266

ABSTRACT

A single bout of high-force exercise has been shown to increase the muscle levels of heat shock proteins (HSPs). Here, changes in the levels of HSPs after 2 and 11 weeks of strength training with either one or three sets per exercise were examined. Fifteen young men (27 ± 6 years, 182 ± 8 cm and 82 ± 13 kg) were randomized to train either one set in lower-body exercises and three sets in upper-body exercises (1L-3UB), or three sets in lower-body exercises and one set in upper-body exercises (3L-1UB). Biopsies from vastus lateralis and trapezius were obtained before, during (2 weeks) and after 11 weeks of strength training (3 bouts per week). The biopsies were analysed for HSP27 (cytosolic and cytoskeletal fractions) and HSP70 and αB-crystallin (cytosolic fraction). No evidence for an effect of training volume (1 vs. 3 sets) on the HSP response was found. For all subjects combined, HSP27 [186 ± 69% (mean ± SD)], HSP70 (146 ± 51%) and αB-crystallin (184 ± 82%) increased in the cytosolic fraction of vastus lateralis after 11 weeks of training. In the trapezius, the only observed increase was for HSP27 in the cytosolic fraction after 2 weeks of training (149 ± 59%). However, the trapezius contained somewhat higher levels of HSP70 and αB-crystallin than vastus lateralis at baseline. The HSP27 levels in the cytoskeletal compartment did not increase significantly in either muscle. In conclusion, strength training resulted-independent of training volume-in elevated levels of HSP27, HSP70 and αB-crystallin in the cytosolic compartment of the vastus lateralis. In the trapezius, only the cytosolic HSP27 levels were increased with training.


Subject(s)
Exercise/physiology , HSP27 Heat-Shock Proteins/metabolism , HSP70 Heat-Shock Proteins/metabolism , Heat-Shock Proteins/metabolism , Muscle, Skeletal/metabolism , Resistance Training , alpha-Crystallin B Chain/metabolism , Adult , Biopsy , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Humans , Male , Quadriceps Muscle , Resistance Training/methods , Young Adult
19.
Eur J Appl Physiol ; 109(2): 343-53, 2010 May.
Article in English | MEDLINE | ID: mdl-20101405

ABSTRACT

This study investigated, in a multi-experiment design, the acute effects of milk protein ingestion, aging [50 young (approximately 26 years) vs. 45 older (approximately 61 years) men] and training state for the blood leukocyte and platelet responses acutely after a single bout of resistance exercise (RE). Moreover, basal effects of 21 weeks of resistance training (RT) were examined. The single bout of RE rapidly increased all blood leukocytes and platelets (P < 0.05). Protein ingestion before or before and after the RE bout did not have an effect on this response. However, younger men had a larger immediate exercise-induced response in leukocytes and platelets than older men. Basal fasting levels of leukocytes and platelets remained unchanged after 21 weeks of RT and this RT period did not change the acute RE-induced leukocyte and platelet response. The long-term RT was, however, able to slightly increase blood hematocrit. Blood platelet counts were consistently higher in the younger men when compared to the older men. Blood lymphopenia occurred only after a larger volume of exercise. In conclusion, the acute increase in blood leukocytes and platelets may be smaller in the older as when compared to the younger men. However, the number of immune cells and thus probably their function may not be affected by milk protein ingestion or months of resistance training.


Subject(s)
Aging/immunology , Exercise/physiology , Milk Proteins/immunology , Resistance Training , Adult , Aged , Humans , Isometric Contraction , Lactic Acid/blood , Leukocyte Count , Male , Middle Aged , Plasma Volume , Platelet Count , Young Adult
20.
Scand J Med Sci Sports ; 20(5): 740-7, 2010 Oct.
Article in English | MEDLINE | ID: mdl-19765242

ABSTRACT

We investigated changes in a large battery of pro- and anti-inflammatory cytokines in elite female soccer players following two 90-min games separated by a 72-h active or passive recovery. Blood samples were taken from 10 players before, within 15-20 min, 21, 45 and 69 h after the first game and within 15-20 min after the second game. The leukocyte count was analyzed, together with several plasma pro- and anti-inflammatory cytokines, using a multiplex bead array system. After the first and second game, the total leukocytes and neutrophils increased significantly. Likewise, increases (P<0.05) in pro-inflammatory cytokines [interleukin (IL)-12, tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), IL-17], chemokines [monocyte chemotactic protein-1 (MCP-1), IL-8 and monokine induced by gamma interferon (MIG)], anti-inflammatory cytokines (IL-2R, IL-4, IL-5, IL-7, IL-10, IL-13, INF-α) and the mixed cytokine IL-6 were observed. Leukocyte and cytokine levels were normalized within 21 h. Active recovery (low-intensity exercises) did not affect the cytokine responses. A dampened cytokine response was observed after the second game as only IL-12, IL-6, MCP-1, IL-8 and MIG increased (P<0.05). In conclusion, a robust pro- and anti-inflammatory cytokine response occurs after the first but not the second soccer game. The implications of the dampened cytokine response in female players after the second game are unknown.


Subject(s)
Cytokines/blood , Inflammation Mediators/blood , Soccer/physiology , Adult , Analysis of Variance , Exercise/physiology , Female , Humans , Leukocyte Count , Statistics, Nonparametric , Time Factors , Young Adult
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