Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Int J Sports Med ; 45(4): 323-221, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38272040

RESUMEN

This study aimed to assess the self-reported frequency and severity of gastrointestinal symptoms (GIS) at rest and around rugby training and match play in male and female rugby union players. An online questionnaire was sent to registered rugby union players (sevens or fifteens). Thirteen GIS were assessed alongside perceptions of appetite around rugby and rest using Likert and visual analog scales. Questions investigating a range of medical and dietary factors were included. Three hundred and twenty-five players (male n=271, female n=54) participated in the study. More frequent GIS (at least one GIS experienced weekly/more often) was reported by players at rest (n=203; 62%) compared to around rugby (n=154; 47%). The overall severity of GIS was low (mild discomfort), but a portion of players (33%) did report symptoms of moderate severity around rugby. Female players reported more frequent and severe symptoms compared to male counterparts (p<0.001). Self-reported appetite was significantly lower after matches compared to training. There were no dietary or medical factors associated with GIS severity scores. This study describes GIS characteristics in male and female rugby union players. Half of the players assessed experienced some form of GIS that may affect nutrition, training, or performance, and should thus be a consideration for practitioners supporting this cohort.


Asunto(s)
Fútbol Americano , Humanos , Masculino , Femenino , Rugby , Estado Nutricional
2.
Eur J Nutr ; 62(7): 2977-2990, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37458775

RESUMEN

PURPOSE: The influence of vitamin D status on exercise-induced immune dysfunction remains unclear. The aim of this study was to investigate the effects of vitamin D status (circulating 25(OH)D) on innate immune responses and metabolomic profiles to prolonged exercise. METHODS: Twenty three healthy, recreationally active males (age 25 ± 7 years; maximal oxygen uptake [[Formula: see text]max] 56 ± 9 mL·kg-1·min-1), classified as being deficient (n = 7) or non-deficient n = 16) according to plasma concentrations of 25(OH)D, completed 2.5 h of cycling at 15% Δ (~ 55-60% [Formula: see text]max). Venous blood and unstimulated saliva samples were obtained before and after exercise. RESULTS: Participants with deficient plasma 25(OH)D on average had lower total lymphocyte count (mean difference [95% confidence interval], 0.5 cells × 109 L [0.1, 0.9]), p = 0.013) and greater neutrophil:lymphocyte ratio (1.3 cells × 109 L, [0.1, 2.5], p = 0.033). The deficient group experienced reductions from pre-exercise to 1 h post-exercise (- 43% [- 70, - 15], p = 0.003) in bacterial stimulated elastase in blood neutrophils compared to non-deficient participants (1% [- 20, 21], p = 1.000) Multivariate analyses of plasma metabolomic profiles showed a clear separation of participants according to vitamin D status. Prominent sources of variation between groups were purine/pyrimidine catabolites, inflammatory markers (linoleic acid pathway), lactate and tyrosine/adrenaline. CONCLUSION: These findings provide evidence of the influence of vitamin D status on exercise-induced changes in parameters of innate immune defence and metabolomic signatures such as markers of inflammation and metabolic stress.


Asunto(s)
Inmunidad Innata , Vitamina D , Masculino , Humanos , Adolescente , Adulto Joven , Adulto , Vitaminas , Ejercicio Físico/fisiología , Neutrófilos
3.
Eur J Appl Physiol ; 122(12): 2545-2554, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36053363

RESUMEN

PURPOSE: To assess indirect markers of intestinal endothelial cell damage and permeability in academy rugby players in response to rugby training at the beginning and end of preseason. METHODS: Blood and urinary measures (intestinal fatty acid binding protein and lactulose:rhamnose) as measures of gastrointestinal cell damage and permeability were taken at rest and after a standardised collision-based rugby training session in 19 elite male academy rugby players (age: 20 ± 1 years, backs: 89.3 ± 8.4 kg; forwards: 111.8 ± 7.6 kg) at the start of preseason. A subsample (n = 5) repeated the protocol after six weeks of preseason training. Gastrointestinal symptoms (GIS; range of thirteen standard symptoms), aerobic capacity (30-15 intermittent fitness test), and strength (1 repetition maximum) were also measured. RESULTS: Following the rugby training session at the start of preseason, there was an increase (median; interquartile range) in intestinal fatty acid binding protein (2140; 1260-2730 to 3245; 1985-5143 pg/ml, p = 0.003) and lactulose:rhamnose (0.31; 0.26-0.34 to 0.97; 0.82-1.07, p < 0.001). After six weeks of preseason training players physical qualities improved, and the same trends in blood and urinary measures were observed within the subsample. Overall, the frequency and severity of GIS were low and not correlated to markers of endothelial damage. CONCLUSIONS: Rugby training resulted in increased intestinal endothelial cell damage and permeability compared to rest. A similar magnitude of effect was observed after six weeks of pre-season training. This was not related to the experience of GIS.


Asunto(s)
Fútbol Americano , Humanos , Masculino , Adulto Joven , Proteínas de Unión a Ácidos Grasos , Fútbol Americano/fisiología , Lactulosa , Permeabilidad , Aptitud Física/fisiología , Ramnosa , Rugby , Intestinos
4.
Eur J Nutr ; 59(4): 1473-1479, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31123862

RESUMEN

PURPOSE: Bovine colostrum is available in health food shops and as a sports food supplement and is rich in antibodies and growth factors including IGF-1. World Anti-Doping Agency advises athletes against taking colostrum for fear of causing increased plasma IGF-1. There are also concerns that colostrum may theoretically stimulate malignancy in organs which express IGF-1 receptors. We, therefore, determined changes in plasma IGF-1 levels in subjects taking colostrum or placebo for 1 day, 4 weeks, and 12 weeks. METHODS: Plasma IGF1 levels were determined in healthy males (n = 16) who ingested 40 g bovine colostrum or placebo along with undertaking moderate exercise for total period of 4.5 h. Two further studies followed changes in IGF1 using double-blind, parallel group, placebo-controlled, randomized trials of colostrum or placebo (N = 10 per arm, 20 g/day for 4 weeks and N = 25 colostrum, N = 29 placebo arm 20 g/day for 12 weeks). RESULTS: Baseline IGF1 levels 130 ± 36 ng/ml. 4.5 h protocol showed no effect of colostrum on plasma IGF1 (ANOVA, treatment group: p = 0.400, group × time: p = 0.498, time p = 0.602). Similarly, no effect of colostrum ingestion was seen following 4 week (ANOVA, group: p = 0.584, group × time interaction: p = 0.083, time p = 0.243) or 12 week (ANOVA, group: p = 0.400, group × time interaction: p = 0.498, time p = 0.602) protocol. CONCLUSIONS: Ingestion of standard recommended doses of colostrum does not increase IGF-1 levels in healthy adults, providing additional support for the safety profile of colostrum ingestion.


Asunto(s)
Calostro/metabolismo , Suplementos Dietéticos , Factor I del Crecimiento Similar a la Insulina/efectos de los fármacos , Administración Oral , Adulto , Animales , Biomarcadores/sangre , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Leche , Valores de Referencia
5.
Eur J Appl Physiol ; 120(7): 1495-1508, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32356023

RESUMEN

PURPOSE: To determine the influence of two commonly occurring genetic polymorphisms on exercise, cognitive performance, and caffeine metabolism, after caffeine ingestion. METHODS: Eighteen adults received caffeine or placebo (3 mg kg-1) in a randomised crossover study, with measures of endurance exercise (15-min cycling time trial; 70-min post-supplementation) and cognitive performance (psychomotor vigilance test; PVT; pre, 50 and 95-min post-supplementation). Serum caffeine and paraxanthine were measured (pre, 30 and 120-min post-supplementation), and polymorphisms in ADORA2A (rs5751876) and CYP1A2 (rs762551) genes analysed. RESULTS: Caffeine enhanced exercise performance (P < 0.001), but effects were not different between participants with ADORA2A 'high' (n = 11) vs. 'low' (n = 7) sensitivity genotype (+ 6.4 ± 5.8 vs. + 8.2 ± 6.8%), or CYP1A2 'fast' (n = 10) vs. 'slow' (n = 8) metabolism genotype (+ 7.2 ± 5.9 vs. + 7.0 ± 6.7%, P > 0.05). Caffeine enhanced PVT performance (P < 0.01). The effect of caffeine was greater for CYP1A2 'fast' vs. 'slow' metabolisers for reaction time during exercise (- 18 ± 9 vs. - 1.0 ± 11 ms); fastest 10% reaction time at rest (- 18 ± 11 vs. - 3 ± 15 ms) and lapses at rest (- 3.8 ± 2.7 vs. + 0.4 ± 0.9) (P < 0.05). There were no PVT differences between ADORA2A genotypes (P > 0.05). Serum caffeine and paraxanthine responses were not different between genotypes (P > 0.05). CONCLUSION: Caffeine enhanced CYP1A2 'fast' metabolisers' cognitive performance more than 'slow' metabolisers. No other between-genotype differences emerged for the effect of caffeine on exercise or cognitive performance, or metabolism.


Asunto(s)
Cafeína/farmacología , Citocromo P-450 CYP1A2/efectos de los fármacos , Ejercicio Físico/fisiología , Genotipo , Receptor de Adenosina A2A/efectos de los fármacos , Adulto , Cafeína/administración & dosificación , Femenino , Humanos , Masculino , Sustancias para Mejorar el Rendimiento/administración & dosificación , Sustancias para Mejorar el Rendimiento/farmacología , Adulto Joven
6.
Eur J Appl Physiol ; 120(10): 2325-2337, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32794058

RESUMEN

PURPOSE: Exertional-heat stress adversely disrupts gastrointestinal (GI) barrier integrity, whereby subsequent microbial translocation (MT) can result in potentially serious health consequences. To date, the influence of aerobic fitness on GI barrier integrity and MT following exertional-heat stress is poorly characterised. METHOD: Ten untrained (UT; VO2max = 45 ± 3 ml·kg-1·min-1) and ten highly trained (HT; VO2max = 64 ± 4 ml·kg-1·min-1) males completed an ecologically valid (military) 80-min fixed-intensity exertional-heat stress test (EHST). Venous blood was drawn immediately pre- and post-EHST. GI barrier integrity was assessed using the serum dual-sugar absorption test (DSAT) and plasma Intestinal Fatty-Acid Binding Protein (I-FABP). MT was assessed using plasma Bacteroides/total 16S DNA. RESULTS: UT experienced greater thermoregulatory, cardiovascular and perceptual strain (p < 0.05) than HT during the EHST. Serum DSAT responses were similar between the two groups (p = 0.59), although Δ I-FABP was greater (p = 0.04) in the UT (1.14 ± 1.36 ng·ml-1) versus HT (0.20 ± 0.29 ng·ml-1) group. Bacteroides/Total 16S DNA ratio was unchanged (Δ; -0.04 ± 0.18) following the EHST in the HT group, but increased (Δ; 0.19 ± 0.25) in the UT group (p = 0.05). Weekly aerobic training hours had a weak, negative correlation with Δ I-FABP and Bacteroides/total 16S DNA responses. CONCLUSION: When exercising at the same absolute workload, UT individuals are more susceptible to small intestinal epithelial injury and MT than HT individuals. These responses appear partially attributable to greater thermoregulatory, cardiovascular, and perceptual strain.


Asunto(s)
Capacidad Cardiovascular , Microbioma Gastrointestinal , Trastornos de Estrés por Calor/fisiopatología , Absorción Intestinal , Adulto , Bacteroides/aislamiento & purificación , Bacteroides/patogenicidad , Ácidos Grasos/metabolismo , Trastornos de Estrés por Calor/metabolismo , Trastornos de Estrés por Calor/microbiología , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Masculino , Esfuerzo Físico , Azúcares/metabolismo
7.
Eur J Nutr ; 58(4): 1441-1451, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29574607

RESUMEN

PURPOSE: Exercise-induced changes in intestinal permeability are exacerbated in the heat. The aim of this study was to determine the effect of 14 days of bovine colostrum (Col) supplementation on intestinal cell damage (plasma intestinal fatty acid-binding protein, I-FABP) and bacterial translocation (plasma bacterial DNA) following exercise in the heat. METHODS: In a double-blind, placebo-controlled, crossover design, 12 males completed two experimental arms (14 days of 20 g/day supplementation with Col or placebo, Plac) consisting of 60 min treadmill running at 70% maximal aerobic capacity (30 °C, 60% relative humidity). Blood samples were collected pre-exercise (Pre-Ex), post-exercise (Post-Ex) and 1 h post-exercise (1 h Post-Ex) to determine plasma I-FABP concentration, and bacterial DNA (for an abundant gut species, Bacteroides). RESULTS: Two-way repeated measures ANOVA revealed an arm × time interaction for I-FABP (P = 0.005, with greater Post-Ex increase in Plac than Col, P = 0.01: Plac 407 ± 194% of Pre-Ex vs Col, 311 ± 134%) and 1 h Post-Ex (P = 0.036: Plac 265 ± 80% of Pre-Ex vs Col, 229 ± 56%). There was no interaction (P = 0.904) but there was a main effect of arm (P = 0.046) for plasma Bacteroides/total bacterial DNA, with lower overall levels evident in Col. CONCLUSION: This is the first investigation to demonstrate that Col can be effective at reducing intestinal injury following exercise in the heat, but exercise responses (temporal pattern) of bacterial DNA were not influenced by Col (although overall levels may be lower).


Asunto(s)
Traslocación Bacteriana/efectos de los fármacos , Ácidos Nucleicos Libres de Células/efectos de los fármacos , Calostro , Suplementos Dietéticos , Calor , Intestinos/efectos de los fármacos , Carrera , Adulto , Animales , Bovinos , Ácidos Nucleicos Libres de Células/sangre , Estudios Cruzados , Método Doble Ciego , Proteínas de Unión a Ácidos Grasos/sangre , Proteínas de Unión a Ácidos Grasos/efectos de los fármacos , Humanos , Humedad , Intestinos/fisiopatología , Masculino
8.
Eur J Nutr ; 58(1): 335-344, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29274034

RESUMEN

BACKGROUND: Bovine colostrum (COL) has been advocated as a nutritional countermeasure to exercise-induced immune dysfunction, but there is a lack of research with clinically relevant in vivo measures. AIM: To investigate the effects of COL supplementation on in vivo immunity following prolonged exercise using experimental contact hypersensitivity (CHS) with the novel antigen diphenylcyclopropenone (DPCP). METHODS: In a double-blind design, 31 men were randomly assigned to COL (20 g/day) or placebo (PLA) for 58 days. Participants ran for 2 h at 60% maximal aerobic capacity on day 28 and received a primary DPCP exposure (sensitisation) 20 min after. On day 56, participants received a low-dose-series DPCP challenge to elicit recall of in vivo immune-specific memory (quantified by skinfold thickness 24 and 48 h later). Analysis of the dose-response curves allowed determination of the minimum dose required to elicit a positive response (i.e., sensitivity). RESULTS: There was no difference in summed skinfold thickness responses between COL and PLA at 24 h (p = 0.124) and 48 h (p = 0.405). However, sensitivity of in vivo immune responsiveness was greater with COL at 24 h (p < 0.001) and 48 h (p = 0.023) with doses ~ twofold greater required to elicit a positive response in PLA. CONCLUSIONS: COL blunts the prolonged exercise-induced decrease in clinically relevant in vivo immune responsiveness to a novel antigen, which may be a mechanism for reduced illness reports observed in the previous studies. These findings also suggest that CHS sensitivity is highly relevant to host defence.


Asunto(s)
Calostro/inmunología , Suplementos Dietéticos , Ejercicio Físico , Tolerancia Inmunológica/efectos de los fármacos , Adolescente , Adulto , Animales , Bovinos , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Tiempo , Adulto Joven
9.
Eur J Nutr ; 57(7): 2529-2536, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28825174

RESUMEN

PURPOSE: Periods of intensified training are associated with immune disturbances, The aim was to investigate the effects of supplementation with Chlorella pyrenoidosa (Chlorella) on secretory IgA (sIgA) responses to 2 days intensified training. METHODS: Twenty-six subjects (age 29.1 ± 8.7 years; VO2max 53.7 ± 11.7 ml kg min-1) provided resting saliva samples for determination of sIgA, at baseline (week-0) and following 4, 5, and 6 weeks (weeks-4, -5, -6) of daily supplementation with 6 g/day Chlorella (n = 13) or placebo (PLA, n = 13). During week-4 a 2-day intensified training period was undertaken [morning and afternoon sessions each day, respectively: VO2max test; high-intensity interval training (HIIT, 3 × 30 s Wingate sprints); 90 min at ~60% VO2max; 3 × 30 s HIIT]. RESULTS: Chlorella increased resting sIgA secretion rate (trial × time, P = 0.016: no change with PLA but increases with Chlorella at week-4, week-5 and week-6, P = 0.020, <0.001, and 0.016). PLA vs Chlorella: week-0 = 54 ± 33 vs 57 ± 37 µg/min; week-4 = 54 ± 35 vs 83 ± 57 µg/min; week-5 = 63 ± 46 vs 98 ± 47 µg/min; week-6 = 58 ± 35 vs 85 ± 59 µg/min. Minimal acute changes in sIgA were seen in response to individual exercise bouts, but it was higher at some times in the Chlorella group (for bouts 2 and 3). CONCLUSION: Supplementation with Chlorella has beneficial effects on resting sIgA, which might be beneficial during periods of intensified training.


Asunto(s)
Chlorella/inmunología , Ejercicio Físico/fisiología , Inmunoglobulina A Secretora/análisis , Adulto , Femenino , Humanos , Inmunoglobulina A , Inmunoglobulina A Secretora/metabolismo , Masculino , Saliva/química , Saliva/inmunología , Saliva/metabolismo
10.
Int J Med Sci ; 15(11): 1217-1226, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30123060

RESUMEN

Background: Exercise-induced muscle damage during intensive sport events is a very common issue in sport medicine. Therefore, the purpose is to investigate the effects of short-term high-dose vitamin C and E supplementation on muscle damage, hemolysis, and inflammatory responses to simulated competitive Olympic Taekwondo (TKD) matches in elite athletes. Methods: Using a randomized placebo-controlled and double-blind study design, eighteen elite male TKD athletes were weight-matched and randomly assigned into either a vitamin C and E group (Vit C+E; N = 9) or placebo group (PLA; N = 9). Vit C+E or PLA supplements were taken daily (Vit C+E: 2000 mg/d vitamin C; 1400 U/d vitamin E) for 4 days (3 days before and on competition day) before taking part in 4 consecutive TKD matches on a single day. Plasma samples were obtained before each match and 24-hours after the first match for determination of markers of muscle damage, hemolysis, and systemic inflammatory state. Results: Myoglobin was lower in the Vit C+E group, compared to PLA, during the match day (area under curve, AUC -47.0% vs. PLA, p = 0.021). Plasma creatine kinase was lower in the Vit C+E group (AUC -57.5% vs. PLA, p = 0.017) and hemolysis was lower in the Vit C+E group (AUC -40.5% vs. PLA, p = 0.034). Conclusions: We demonstrated that short-term (4-days) vitamin C and E supplementation effectively attenuated exercise-induced tissue damage and inflammatory response during and after successive TKD matches.


Asunto(s)
Ácido Ascórbico/uso terapéutico , Inflamación/prevención & control , Artes Marciales , Músculo Esquelético/lesiones , Vitamina E/uso terapéutico , Vitaminas/uso terapéutico , Suplementos Dietéticos , Método Doble Ciego , Humanos , Masculino , Adulto Joven
11.
Eur J Appl Physiol ; 117(5): 931-941, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28290057

RESUMEN

PURPOSE: Intestinal cell damage due to physiological stressors (e.g. heat, oxidative, hypoperfusion/ischaemic) may contribute to increased intestinal permeability. The aim of this study was to assess changes in plasma intestinal fatty acid-binding protein (I-FABP) in response to exercise (with bovine colostrum supplementation, Col, positive control) and compare this to intestinal barrier integrity/permeability (5 h urinary lactulose/rhamnose ratio, L/R). METHODS: In a double-blind, placebo-controlled, crossover design, 18 males completed two experimental arms (14 days of 20 g/day supplementation with Col or placebo, Plac). For each arm participants performed two baseline (resting) intestinal permeability assessments (L/R) pre-supplementation and one post-exercise following supplementation. Blood samples were collected pre- and post-exercise to determine I-FABP concentration. RESULTS: Two-way repeated measures ANOVA revealed an arm × time interaction for L/R and I-FABP (P < 0.001). Post hoc analyses showed urinary L/R increased post-exercise in Plac (273% of pre, P < 0.001) and Col (148% of pre, P < 0.001) with post-exercise values significantly lower with Col (P < 0.001). Plasma I-FABP increased post-exercise in Plac (191% of pre-exercise, P = 0.002) but not in the Col arm (107%, P = 0.862) with post-exercise values significantly lower with Col (P = 0.013). Correlations between the increase in I-FABP and L/R were evident for visit one (P = 0.044) but not visit two (P = 0.200) although overall plots/patterns do appear similar for each. CONCLUSION: These findings suggest that exercise-induced intestinal cellular damage/injury is partly implicated in changes in permeability but other factors must also contribute.


Asunto(s)
Ejercicio Físico , Proteínas de Unión a Ácidos Grasos/sangre , Absorción Intestinal , Mucosa Intestinal/metabolismo , Adulto , Animales , Bovinos , Calostro , Humanos , Lactulosa/orina , Masculino , Ramnosa/orina
12.
Eur J Nutr ; 55(4): 1583-93, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26163337

RESUMEN

BACKGROUND: Carbohydrate (CHO) supplementation during prolonged exercise is widely acknowledged to blunt in vitro immunoendocrine responses, but no study has investigated in vivo immunity. PURPOSE: To determine the effect of CHO supplementation during prolonged exercise on in vivo immune induction using experimental contact hypersensitivity with the novel antigen diphenylcyclopropenone (DPCP). METHODS: In a double-blind design, 32 subjects were randomly assigned to 120 min of treadmill exercise at 60 % [Formula: see text] with CHO (Ex-CHO) or placebo (Ex-PLA) supplementation. Responses were also compared to 16 resting control (CON) subjects from a previous study (for additional comparison with a resting non-exercise condition). Standardised diets (24 h pre-trial) and breakfasts (3.5 h pre-trial) were provided. Subjects received a primary DPCP exposure (sensitisation) 20 min after trial completion, and exactly 28 days later the strength of immune reactivity was quantified by magnitude of the cutaneous response (skin-fold thickness and erythema) to a low dose-series DPCP challenge. Stress hormones and leucocyte trafficking were also monitored. RESULTS: CHO supplementation blunted the cortisol and leucocyte trafficking responses, but there was no difference (P > 0.05) between Ex-CHO and Ex-PLA in the in vivo immune responses (e.g. both ~46 % lower than CON for skin-fold response). CONCLUSIONS: CHO supplementation does not influence the decrease in in vivo immunity seen after prolonged exercise. The effects with more stressful (or fasted) exercise remain to be determined. However, there appears to be no benefit under the conditions of the present study, which have practical relevance to what many athletes do in training or competition.


Asunto(s)
Carbohidratos de la Dieta/administración & dosificación , Suplementos Dietéticos , Ejercicio Físico/fisiología , Tolerancia Inmunológica , Adulto , Ciclopropanos/inmunología , Dieta , Método Doble Ciego , Eritema/sangre , Eritema/inmunología , Prueba de Esfuerzo , Humanos , Hidrocortisona/sangre , Hipersensibilidad/sangre , Hipersensibilidad/inmunología , Recuento de Leucocitos , Leucocitos/inmunología , Masculino , Consumo de Oxígeno , Descanso , Adulto Joven
13.
Lung ; 194(6): 881-887, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27530251

RESUMEN

PURPOSE: The underlying biological mechanisms of the frequent exacerbator phenotype of COPD remain unclear. We compared systemic neutrophil function in COPD patients with or without frequent exacerbations. METHODS: Whole blood from COPD frequent exacerbators (defined as ≥2 moderate-severe exacerbations in the previous 2 years) and non-exacerbators (no exacerbations in the preceding 2 years) was assayed for neutrophil function. Neutrophil function in healthy ex-smoking volunteers was also measured as a control (reference) group. RESULTS: A total of 52 subjects were included in this study: 26 frequent exacerbators, 18 non-exacerbators and 8 healthy controls. COPD frequent exacerbators had blunted blood neutrophil fMLP-stimulated oxidative burst compared to both non-exacerbators (p < 0.01) and healthy controls (p < 0.001). There were no differences between COPD frequent exacerbators and non-exacerbators in blood neutrophil PMA-stimulated oxidative burst, but both COPD groups had reduced responses compared to healthy controls (p < 0.001). Bacterial-stimulated neutrophil degranulation was greater in frequent exacerbators than non-exacerbators (p < 0.05). CONCLUSION: This study is the first to report aberrant receptor-mediated blood neutrophil function in the frequent exacerbator of COPD.


Asunto(s)
Degranulación de la Célula , Progresión de la Enfermedad , Neutrófilos/fisiología , Enfermedad Pulmonar Obstructiva Crónica/sangre , Brote de los Síntomas , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , N-Formilmetionina Leucil-Fenilalanina/farmacología , Prueba de Estudio Conceptual , Estallido Respiratorio/efectos de los fármacos , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacología
14.
Brain Behav Immun ; 39: 194-203, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24200515

RESUMEN

Bovine colostrum (COL) has been advocated as a nutritional countermeasure to exercise-induced immune dysfunction and increased risk of upper respiratory illness (URI) in athletic populations, however, the mechanisms remain unclear. During winter months, under double-blind procedures, 53 males (mean training load±SD, 50.5±28.9 MET-hweek(-1)) were randomized to daily supplementation of 20g of COL (N=25) or an isoenergetic/isomacronutrient placebo (PLA) (N=28) for 12weeks. Venous blood was collected at baseline and at 12weeks and unstimulated saliva samples at 4 weeks intervals. There was a significantly lower proportion of URI days and number of URI episodes with COL compared to PLA over the 12weeks (p<0.05). There was no effect of COL on in vitro neutrophil oxidative burst, salivary secretory IgA or salivary antimicrobial peptides (p>0.05), which does not support previously suggested mechanisms. In a subset of participants (COL=14, PLA=17), real-time quantitative PCR, targeting the 16S rRNA gene showed there was an increase in salivary bacterial load over the 12 weeks period with PLA (p<0.05) which was not as evident with COL. Discriminant function analysis of outputs received from serum metabolomics showed changes across time but not between groups. This is the first study to demonstrate that COL limits the increased salivary bacterial load in physically active males during the winter months which may provide a novel mechanism of immune-modulation with COL and a relevant marker of in vivo (innate) immunity and risk of URI.


Asunto(s)
Calostro/inmunología , Ejercicio Físico/fisiología , Infecciones del Sistema Respiratorio/prevención & control , Animales , Antiinfecciosos/farmacología , Bovinos , Método Doble Ciego , Humanos , Inmunoglobulina A Secretora/metabolismo , Masculino , Neutrófilos/fisiología , Estallido Respiratorio , Infecciones del Sistema Respiratorio/tratamiento farmacológico
15.
Eur J Appl Physiol ; 113(6): 1511-22, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23288035

RESUMEN

Acute tyrosine administration is associated with increased exercise capacity in the heat. To explore whether reduced plasma tyrosine and phenylalanine (tyrosine precursor) is associated with impaired exercise capacity in the heat, eight healthy, moderately trained male volunteers, unacclimated to exercise in the heat, performed two tests in a crossover design separated by at least 7 days. In a randomised, double-blind fashion, subjects ingested 500 mL flavoured, sugar-free water containing amino acids [(TYR-free; isoleucine 15 g, leucine 22.5 g, valine 17.5 g, lysine 17.5 g, methionine 5 g, threonine 10 g, tryptophan 2.5 g)] to lower the ratio of plasma tyrosine plus phenylalanine:amino acids competing for blood-brain barrier uptake (CAA), a key determinant of brain uptake, or a balanced mixture (BAL; TYR-free plus 12.5 g tyrosine and 12.5 g phenylalanine). One hour later, subjects cycled to exhaustion at 63 ± 5 % [Formula: see text]O2peak in 30 °C and 60 % relative humidity. Pre-exercise ratio of plasma tyrosine plus phenylalanine:ΣCAA declined 75 ± 5 % from rest in TYR-free (P < 0.001), but was unchanged in BAL (P = 0.061). Exercise time was shorter in TYR-free (59.8 ± 19.0 min vs. 66.2 ± 16.9 min in TYR-free and BAL respectively; P = 0.036). Heart rate (P = 0.298), core (P = 0.134) and skin (P = 0.384) temperature, RPE (P > 0.05) and thermal sensation (P > 0.05) were similar at exhaustion in both trials. These data indicate that acutely depleting plasma catecholamine precursors:ΣCAA is associated with reduced submaximal exercise capacity in the heat.


Asunto(s)
Tolerancia al Ejercicio/efectos de los fármacos , Calor , Fenilalanina/sangre , Tirosina/sangre , Administración Oral , Adulto , Estudios Cruzados , Método Doble Ciego , Humanos , Humedad , Masculino , Fenilalanina/administración & dosificación , Fenilalanina/farmacología , Tirosina/administración & dosificación , Tirosina/farmacología
16.
Parkinsonism Relat Disord ; 110: 105366, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36996674

RESUMEN

INTRODUCTION: Individuals with Parkinson's Disease (PD) can develop a range of motor and non-motor symptoms due to its progressive nature and lack of effective treatments. Exercise interventions, such as multimodal (MM) programmes, may improve and sustain physical or cognitive function in PD. However, studies usually evaluate physical performance, cognition, and neuroprotective biomarkers separately and over short observation periods. METHODS: Part one evaluates the effects of a weekly community-based MM exercise class (60 min) on physical function in people with PD (PwP). Exercise participants (MM-EX; age 65 ± 9 years; Hoehn and Yahr (H&Y) scale ≤ IV) completed a battery of functional assessments every 4 months for one (n = 27), two (n = 20) and three years (n = 15). In part two, cognition and brain-derived neurotrophic factor (BDNF) levels were assessed over 6-to-8 months and compared to aged-matched non-active PwP (na-PD, n = 16; age 68 ± 7 years; H&Y scale ≤ III) and healthy older adults (HOA, n = 18; age 61 ± 6 years). RESULTS: MM-EX significantly improved walking capacity (5% improvement after 8 months), functional mobility (11% after 4 months), lower extremity strength (15% after 4 months) and bilateral grip strength (9% after 28 months), overall, maintaining physical function across 3 years. Group comparisons showed that only MM-EX significantly improved their mobility, lower extremity strength, cognition and BDNF levels. CONCLUSION: Weekly attendance to a community-based MM exercise group session can improve and maintain physical and cognitive function in PD, with the potential to promote neuroprotection.


Asunto(s)
Enfermedad de Parkinson , Humanos , Anciano , Persona de Mediana Edad , Enfermedad de Parkinson/terapia , Factor Neurotrófico Derivado del Encéfalo , Terapia por Ejercicio , Ejercicio Físico , Caminata
17.
Eur J Nutr ; 51(1): 69-79, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21465244

RESUMEN

PURPOSE: Acute antioxidant supplementation may modulate oxidative stress and some immune perturbations that typically occur following prolonged exercise. The aims of the present study were to examine the effects of acutely consuming dark chocolate (high polyphenol content) on plasma antioxidant capacity, markers of oxidative stress and immunoendocrine responses to prolonged exercise. METHODS: Fourteen healthy men cycled for 2.5 h at ~60% maximal oxygen uptake 2 h after consuming 100 g dark chocolate (DC), an isomacronutrient control bar (CC) or neither (BL) in a randomised-counterbalanced design. RESULTS: DC enhanced pre-exercise antioxidant status (P = 0.003) and reduced by trend (P = 0.088) 1 h post-exercise plasma free [F2-isoprostane] compared with CC (also, [F2-isoprostane] increased post-exercise in CC and BL but not DC trials). Plasma insulin concentration was significantly higher pre-exercise (P = 0.012) and 1 h post-exercise (P = 0.026) in the DC compared with the CC trial. There was a better maintenance of plasma glucose concentration on the DC trial (2-way ANOVA trial × time interaction P = 0.001), which decreased post-exercise in all trials but was significantly higher 1 h post-exercise (P = 0.039) in the DC trial. There were no between trial differences in the temporal responses (trial × time interactions all P > 0.05) of hypothalamic-pituitary-adrenal axis stress hormones, plasma interleukin-6, the magnitude of leukocytosis and neutrophilia and changes in neutrophil function. CONCLUSION: Acute DC consumption may affect insulin, glucose, antioxidant status and oxidative stress responses, but has minimal effects on immunoendocrine responses, to prolonged exercise.


Asunto(s)
Antioxidantes/análisis , Cacao , Dulces , Inmunomodulación , Células Secretoras de Insulina/metabolismo , Estrés Oxidativo , Resistencia Física , Adulto , Antioxidantes/administración & dosificación , Ciclismo , Biomarcadores/sangre , Glucemia/análisis , Catequina/administración & dosificación , Catequina/sangre , F2-Isoprostanos/sangre , Humanos , Insulina/sangre , Masculino , Neutrófilos/inmunología , Método Simple Ciego , Factores de Tiempo , Adulto Joven
19.
Res Q Exerc Sport ; 93(4): 861-868, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-34806947

RESUMEN

Introduction: Team sport athletes have increased susceptibility to upper respiratory symptoms (URS) during periods of intensified training and competition. Reactivation of Epstein-Barr Virus (EBV) may be a novel marker for risk of upper respiratory illness (URI) in professional athletes. Aims: To investigate changes in salivary EBV DNA (in addition to the well-established marker, salivary secretory immunoglobulin A), and incidence of URS in professional footballers. Methods: Over a 16-week period (August to November 2016), 15 male players from a professional English football League 1 club provided weekly unstimulated saliva samples (after a rest day) and recorded URS. Saliva samples were analyzed for secretory IgA (ELISA) and EBV DNA (qPCR). Results: Whole squad median (interquartile range) saliva IgA concentration and secretion rate significantly decreased (p < .05) between weeks 8 and 12 (concentration, 107 (76-150) mg/L healthy baseline to 51 (31-80) mg/L at week 12; secretion rate 51 (30-78) µg/min healthy baseline to 22 (18-43) µg/min at week 12). Two players reported URS episodes during week 10, both after IgA secretion rate decreased below 40% of the individual's healthy baseline. EBV DNA was detected in the weeks before URS but also at other times and in healthy players (overall frequency 40%, range 11-78%) and frequency was similar between the URS and healthy group. Conclusion: These findings confirm salivary IgA as a useful marker of URS risk but EBV DNA was not. Further research capturing a greater number of URS episodes is required, however, to fully determine the utility of this marker.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Fútbol , Humanos , Masculino , Herpesvirus Humano 4/genética , Inmunoglobulina A Secretora/análisis , Saliva/química , Biomarcadores
20.
PLoS One ; 17(4): e0266379, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35417467

RESUMEN

Nutrition strategies and supplements may have a role to play in diminishing exercise associated gastrointestinal cell damage and permeability. The aim of this systematic review was to determine the influence of dietary supplements on markers of exercise-induced gut endothelial cell damage and/or permeability. Five databases were searched through to February 2021. Studies were selected that evaluated indirect markers of gut endothelial cell damage and permeability in response to exercise with and without a specified supplement, including with and without water. Acute and chronic supplementation protocols were included. Twenty-seven studies were included. The studies investigated a wide range of supplements including bovine colostrum, glutamine, probiotics, supplemental carbohydrate and protein, nitrate or nitrate precursors and water across a variety of endurance exercise protocols. The majority of studies using bovine colostrum and glutamine demonstrated a reduction in selected markers of gut cell damage and permeability compared to placebo conditions. Carbohydrate intake before and during exercise and maintaining euhydration may partially mitigate gut damage and permeability but coincide with other performance nutrition strategies. Single strain probiotic strains showed some positive findings, but the results are likely strain, dosage and duration specific. Bovine colostrum, glutamine, carbohydrate supplementation and maintaining euhydration may reduce exercise-associated endothelial damage and improve gut permeability. In spite of a large heterogeneity across the selected studies, appropriate inclusion of different nutrition strategies could mitigate the initial phases of gastrointestinal cell disturbances in athletes associated with exercise. However, research is needed to clarify if this will contribute to improved athlete gastrointestinal and performance outcomes.


Asunto(s)
Glutamina , Nitratos , Animales , Biomarcadores , Carbohidratos , Bovinos , Suplementos Dietéticos , Humanos , Permeabilidad , Agua
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA