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2.
Aust N Z J Psychiatry ; 57(5): 698-709, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-35957548

RESUMEN

OBJECTIVE: To measure symptoms of anxiety, depression and hopelessness in a sample of young Pacific adults living in Auckland, New Zealand during the 2020/2021 COVID-19 pandemic and identify protective factors. METHODS: Participants were 267 Pacific adults (58% female) who completed a survey online. Analyses included descriptive statistics, correlations, linear regression and symptom network analysis. RESULTS: Around 25% of the sample scored in the range for moderate to severe anxiety and 10% for moderate to severe depression on standard measures. Almost 40% indicated that they found the first lockdown very stressful and 55% noted that some members of their family found it stressful. Only 16% worried about COVID-19 and their future quite a bit or constantly, while another 25% worried sometimes. Self-compassion and Pacific Identity had moderate, negative correlations, and Worry about COVID-19 had weak positive correlations, with anxiety, depression, hopelessness and perceived stress. CONCLUSION: These results suggest that, while the prevalence of depression and anxiety are quite high among this population, fostering ethnic identity and self-compassion in Pacific children and adolescents might protect against developing depression and anxiety.


Asunto(s)
COVID-19 , Adolescente , Niño , Adulto , Humanos , Femenino , Masculino , COVID-19/epidemiología , Depresión/epidemiología , Pandemias , Nueva Zelanda/epidemiología , Salud Mental , Control de Enfermedades Transmisibles , Ansiedad/epidemiología
4.
Eur J Sport Sci ; 22(12): 1827-1835, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34873991

RESUMEN

ABSTRACTThe primary aim of this study was to examine if biomarker and/or self-reported data could predict upper respiratory tract symptom (URTS) risk in elite field hockey players. The secondary aim was to investigate the effect of the additional stressor 'repeated heat exposure' on measures of thermoregulation and immunity. A prospective cohort repeated measures study design was used to collect URTS, household illness, self-reported wellness, biomarker and thermoregulatory data from elite male field hockey players (n = 19), during an 8-week training and competition period that simulated the preparatory and competition phases of the 2020 Tokyo Olympics. Heat response testing (HRT) was performed at the beginning of the study period, following heat acclimation (HA) and following an intensified competition period (ICP) played in hot and humid conditions (27-37°C and 53-80% relative humidity). Univariate frailty analysis demonstrated that illness in players' households (Hazard ratio (HR: 4.90; p < 0.001)) and self-reported stress (HR: 0.63; p = 0.043) predicted players' risk for URTS. Additionally, low baseline resting salivary secretory immunoglobulin A (SIgA) concentration predicted players' "potential" URTS risk (p = 0.021). The additional stressor "repeated heat exposure" was found to facilitate partial thermoregulatory adaptation without attenuating resting immune functions. In conclusion, lifestyle and behavioural factors (i.e. household illness and stress) influenced players risk for URTS more so than sport-related stressors. Furthermore, repeated heat exposure did not appear to compromise players resting immunity. To assess athletes' risk for URTS, baseline screening of SIgA concentration and regular monitoring of self-reported lifestyle and behavioural data are recommended.Highlights Self-reported illness in players' households and higher self-reported stress significantly predicted increased upper respiratory tract symptom risk.Low baseline salivary secretory immunoglobulin A concentration predicted players "potential" URTS risk.Repeated heat exposures facilitated partial thermoregulatory adaptation without altering resting immunity.


Asunto(s)
Hockey , Humanos , Masculino , Hockey/fisiología , Estudios Prospectivos , Tokio , Inmunoglobulina A Secretora , Biomarcadores , Sistema Respiratorio
5.
Nutrients ; 13(12)2021 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-34959829

RESUMEN

Bread, a frequently consumed food, is an ideal vehicle for addition of ingredients that increase nutrient density and add health benefits. This experimental cross-over study sought to test the effect of a vegetable-enriched bread (VB) in comparison to commercial white bread (WB) and wheatmeal bread (WMB) on serum glucose, insulin response and subjective appetite suppression. On three separate occasions, 10 participants (23 ± 7 years) visited the laboratory and consumed after an overnight fast, in random order, a 75 g serve of WB, WMB or VB. Venous blood samples drawn twice before (0 min) and at 15, 30, 45, 60, 90 and 120 min after consumption of the bread were analysed for glucose and insulin. Participants rated their subjective feelings of hunger, fullness, satisfaction and desire to eat on a 150 mm Likert scale. The mean glucose iAUC over 120 min was not different among the breads. The mean insulin iAUC for the VB was significantly lower than the WB and WMB; difference VB and WB 12,415 pmol/L*minutes (95% CI 1918, 22,912 pmol/L*minutes, p = 0.025) and difference VB and WMB 13,800 pmol/L*minutes (95% CI 1623, 25,976 pmol/L*minutes p = 0.031). The VB was associated with a higher fullness feeling in the participants over the 120-min period. The consumption of VB was associated with less insulin release and higher satiety over 120 min which may be related to the higher fibre content and texture of VB. The role of vegetable and fruit fibres such as pectin in bread and insulin response should also be further explored.


Asunto(s)
Apetito/fisiología , Pan/análisis , Alimentos Fortificados/análisis , Índice Glucémico/fisiología , Verduras , Adulto , Área Bajo la Curva , Glucemia/metabolismo , Estudios Cruzados , Fibras de la Dieta/farmacología , Femenino , Humanos , Insulina/sangre , Masculino , Periodo Posprandial , Respuesta de Saciedad/fisiología , Adulto Joven
6.
BMC Public Health ; 21(1): 2020, 2021 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-34742271

RESUMEN

BACKGROUND: Breast cancer is the most common cancer in New Zealand, with approximately 3000 new registrations annually, affecting one in nine women and resulting in more than 600 deaths. This study analyzed data of patients with selected prognostic factors of Nottingham grade 3 tumors over a specified five-year period. The study aimed to identify factors that result in differential survival in the female, New Zealand population. METHOD: This is an observational, retrospective cohort study of prospectively collected data from New Zealand Breast Cancer Register. The selected period of 1st January 2011 to 31st, December 2015 allowed a consistent overlap for a national five-year data of grade 3 breast cancer in New Zealand. Mortality was carried out using univariate Fine-Gray competing risk statistical models. RESULTS: This study showed that women in the older age group (> 70 years) had higher five-year mortality risk (HR: 1.7, 95% CI: 0.9-3.0, p = 0.053). Hormonal receptor analysis showed that ER positive, PR negative, and ER negative, PR negative subjects were at increased risk (HR = 3.5, 95% CI 2.3-5.4, p < 0.001) and (HR = 2.6, 95% CI, 1.8-3.9, p < 0.001) respectively. Molecular subtypes Triple Negative Breast Cancer and Luminal B subjects were at increased risk (HR = 3.0, 95% CI, 1.8-4.7, p < 0.001 and (HR = 3.3, 95% CI, 1.7-6.3, p < 0.001) respectively. HER2 enriched subjects were at a higher, but not significant, risk of five-year mortality compared to luminal A (HR = 1.6, 95% CI, 0.8-3.0, p = 0.10). NZ Europeans were at increased risk (HR = 1.7, 95% CI, 0.8-3.2, p = 0.11), with the highest Cumulative Incidence Function CIF, the largest proportion of HER2 enriched and TNBC across ethnicities.; however, Pacific Islanders experienced the highest HER2 CIF. CONCLUSION: The survival rates for grade 3 breast cancer vary across the selected prognostic factors and ethnicity. The results of this study make an initial contribution to the understanding of grade 3 breast cancer in the New Zealand population.


Asunto(s)
Neoplasias de la Mama , Receptores de Progesterona , Anciano , Femenino , Humanos , Nueva Zelanda/epidemiología , Pronóstico , Receptores de Estrógenos , Estudios Retrospectivos , Factores de Riesgo
7.
J Fish Biol ; 99(2): 684-689, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33811326

RESUMEN

We sought to determine a compatible anticoagulant for routine haematological and physiological assessments with giant kokopu (Galaxias argenteus), an endemic New Zealand fish. We observed that blood treated with lithium heparin (LH) rapidly coagulated and haemolysed, making it unsuitable for G. argenteus. Dipotassium ethylenediaminetetraacetic acid (K2 EDTA) and trisodium citrate (citrate) effectively prevented blood coagulation. K2 EDTA-treated erythrocytes exhibited the least mean haemolysis and mean corpuscular fragility. Further studies into prolonged storage effects of citrate and K2 EDTA are recommended to find a compatible anticoagulant for use with G. argenteus blood.


Asunto(s)
Anticoagulantes , Heparina , Animales , Anticoagulantes/farmacología , Ácido Edético/farmacología , Eritrocitos , Peces , Heparina/farmacología
8.
J Fish Biol ; 99(2): 384-395, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33715165

RESUMEN

This study characterized selected peripheral blood (PB) haematological parameters, liver, serum and muscle metabolic features in 3- and 5-year-old male and female giant kokopu (Galaxias argenteus) broodstock reared indoor at 16°C. Sex and age did not affect PB total cell count and haematocrit values. Nonetheless, higher erythrocytes in 5-year-old fish, elevated thrombocyte and lymphocyte counts in 3-year-old fish indicate age-specific cellular regulation. Higher thrombocyte counts in female fish suggest sex-specific regulation. At a metabolic level, liver abundance for long chain saturated fatty acids (FAs) was higher in males, whereas females had elevated levels of polyunsaturated FAs. Essential and non-essential amino acids (AAs) in liver and serum were also elevated in females compared to males. These findings suggest differential allocation of FAs and AAs to reflect requirements for gonadal, development and provisioning. Similarly, age significantly resulted in higher liver and serum abundances of some non-essential AAs in 3-year-olds compared to 5-year-old fish, suggesting higher metabolism in younger fish. Overall, results enhance our understanding of sex- and age-based differences in fish haematology, muscle, liver, and serum metabolite profiles in healthy G. argenteus. Future studies should carefully consider potential age- and sex-specific differences in metabolic responses.


Asunto(s)
Ácidos Grasos , Metaboloma , Animales , Ácidos Grasos Insaturados , Femenino , Peces , Gónadas , Masculino
9.
Int J Sports Physiol Perform ; 16(8): 1204­1207, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-33735834

RESUMEN

Many endurance athletes perform specific blocks of training in hot environments in "heat stress training camps." It is not known if physiological threshold heart rates measured in temperate conditions are reflective of those under moderate environmental heat stress. A total of 16 endurance-trained cyclists and triathletes performed incremental exercise assessments in 18°C and 35°C (both 60% relative humidity) to determine heart rates at absolute blood lactate and ventilatory thresholds. Heart rate at fixed blood lactate concentrations of 2, 3, and 4 mmol·L-1 and ventilatory thresholds were not significantly different between environments (P > .05), despite significant heat stress-induced reductions in power output of approximately 10% to 17% (P < .05, effect size = 0.65-1.15). The coefficient of variation for heart rate at these blood lactate concentrations (1.4%-2.9%) and ventilatory thresholds (2.3%-2.7%) between conditions was low, with significant strong positive correlations between measurements in the 2 environments (r = .92-.95, P < .05). These data indicate heart rates measured at physiological thresholds in temperate environments are reflective of measurements taken under moderate environmental heat stress. Therefore, endurance athletes embarking on heat stress training camps can use heart rate-based thresholds ascertained in temperate environments to prescribe training under moderate environmental heat stress.


Asunto(s)
Aclimatación , Calor , Aclimatación/fisiología , Frecuencia Cardíaca , Respuesta al Choque Térmico , Humanos , Ácido Láctico , Masculino
10.
J Sports Sci ; 39(14): 1594-1601, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33629651

RESUMEN

This study examined possible predictors of upper respiratory tract symptom (URTS) episodes in elite rugby union and league players (n = 51) during intensive pre-season training. Baseline saliva and blood samples were collected in the first week of pre-season training for analysis of salivary secretory immunoglobulin A (SIgA) and cytomegalovirus. Thereafter, SIgA, URTS, internal training load and self-reported wellness data were repeatedly measured throughout a 10-week pre-season training period. Univariate frailty model analysis, which included 502 observations, was performed for each rugby code for the following independent predictor variables: SIgA concentration, internal training load, total wellness, sleep quantity, sleep quality and stress. Rugby union and league players experienced a similar number of URTS episodes; however, predictors of URTS episodes differed between the codes. No biomarkers or self-reported measures significantly predicted URTS risk in rugby union players, while reductions in self-reported total wellness (HR: 0.731, p = 0.004) and sleep quality (HR: 0.345, p = 0.001) predicted increased URTS risk in rugby league players. The findings from this study highlight that factors influencing URTS risk are perhaps sport specific and this may be attributed to different sporting demands and/or different management of players by team-practitioners.


Asunto(s)
Citomegalovirus/aislamiento & purificación , Fútbol Americano/fisiología , Inmunoglobulina A Secretora/metabolismo , Acondicionamiento Físico Humano/fisiología , Infecciones del Sistema Respiratorio/epidemiología , Adulto , Biomarcadores/metabolismo , Estudios de Cohortes , Humanos , Incidencia , Masculino , Nueva Zelanda/epidemiología , Estudios Prospectivos , Factores de Riesgo , Encuestas y Cuestionarios , Adulto Joven
11.
Nutrients ; 13(1)2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33450885

RESUMEN

We have previously shown that probiotic supplementation with Lactobacillus rhamnosus HN001 (HN001) led to a reduced incidence of gestational diabetes mellitus (GDM). Here we investigate whether HN001 supplementation resulted in alterations in fasting lipids, insulin resistance, or bile acids (BAs) during pregnancy. Fasting plasma samples collected at 24-30 weeks' gestation, from 348 women randomised at 14-16 weeks' gestation to consume daily probiotic HN001 (n = 172) or a placebo (n = 176) were analysed for lipids, insulin, glucose and BAs. Women supplemented with HN001 had lower fasting glucose compared with placebo (p = 0.040), and lower GDM. Significant differences were found in fasting insulin, HOMA-IR, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein (HDL)-c, triglycerides, total cholesterol, and BAs by GDM status. Lower fasting conjugated BAs were seen in women receiving HN001. A significant decrease of glycocholic acid (GCA) was found in older (age ≥ 35) women who received HN001 (p = 0.005), while GDM women showed significant reduced taurodeoxycholic acid (TDCA) (p = 0.018). Fasting conjugated BA was positively correlated with fasting glucose (r = 0.136, p = 0.020) and fasting insulin (r = 0.113, p = 0.036). Probiotic HN001 supplementation decreases conjugated BAs and might play a role in the improvement of glucose metabolism in women with pregnancy.


Asunto(s)
Ácidos y Sales Biliares/sangre , Suplementos Dietéticos , Lacticaseibacillus rhamnosus/fisiología , Probióticos/administración & dosificación , Adulto , Biomarcadores , Glucemia , Cromatografía Liquida , Diabetes Gestacional , Femenino , Humanos , Insulina/metabolismo , Lípidos/sangre , Espectrometría de Masas , Persona de Mediana Edad , Embarazo , Adulto Joven
12.
Scand J Med Sci Sports ; 31(1): 140-152, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32969535

RESUMEN

This study examined the effect of short-term adaptation to a ketogenic diet (KD) on resting and post-exercise immune markers. Using a randomized, repeated-measures, crossover design, eight trained, male, endurance athletes ingested a 31-day low carbohydrate (CHO), KD (energy intake: 4% CHO; 78% fat) or their habitual diet (HD) (energy intake: 43% CHO; 38% fat). On days 0 and 31, participants ran to exhaustion at 70% VO2max . A high-CHO (2 g·kg-1 ) meal was ingested prior to the pre-HD, post-HD, and pre-KD trials, with CHO (~55 g·h-1 ) ingested during exercise, whereas a low-CHO (<10 g) meal was ingested prior to the post-KD trial, with fat ingested during exercise. Blood and saliva samples were collected at pre-exercise, exhaustion, and 1 hour post-exhaustion. T-cell-related cytokine gene expression within peripheral blood mononuclear cells (PBMCs) and whole-blood inflammatory cytokine production were determined using 24-hour multi-antigen-stimulated whole-blood cultures. Multi-antigen-stimulated PBMC IFN-γ mRNA expression and the IFN-γ/IL-4 mRNA expression ratio were higher at exhaustion in the post-KD compared with pre-KD trial (P = 0.003 and P = 0.004); however, IL-4 and IL-10 mRNA expression were unaltered (P > 0.05). Multi-antigen-stimulated whole-blood IL-10 production was higher in the post-KD compared with pre-KD trial (P = 0.028), whereas IL-1ß, IL-2, IL-8, and IFN-γ production was lower in the post-HD compared with pre-HD trial (P < 0.01). Salivary immunoglobulin A (SIgA) secretion rate was higher in the post-KD compared with pre-KD trial (P < 0.001). In conclusion, short-term adaptation to a KD in endurance athletes may alter the pro- and anti-inflammatory immune cell cytokine response to a multi-antigen in vitro and SIgA secretion rate.


Asunto(s)
Inmunidad Adaptativa , Dieta Cetogénica , Inmunidad Mucosa , Resistencia Física/inmunología , Ácido 3-Hidroxibutírico/sangre , Biomarcadores/sangre , Glucemia/metabolismo , Estudios Cruzados , Citocinas/sangre , Expresión Génica , Humanos , Hidrocortisona/sangre , Inmunoglobulina A/metabolismo , Interferón gamma/genética , Interleucina-10/genética , Interleucina-4/genética , Leucocitos Mononucleares/inmunología , Masculino , ARN Mensajero/genética , Saliva/inmunología
13.
J Sci Med Sport ; 24(5): 430-434, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33262041

RESUMEN

OBJECTIVES: To identify periods of increased risk for upper respiratory tract symptom (URTS) episodes, and examine whether biomarkers and/or self-reported lifestyle and wellness data can predict URTS risk in elite rugby union players. DESIGN: Prospective, longitudinal and repeated-measures study. METHODS: Salivary secretory immunoglobulin A (SIgA), salivary cortisol, URTS, internal training load and self-reported lifestyle and wellness data including household illness, stress, mood, fatigue, muscle soreness and sleep quality were repeatedly measured in elite Southern hemisphere rugby union players (n=28) throughout a season. Univariate frailty model analysis, which included 495 observations, was used to determine predictors of URTS risk. RESULTS: Surprisingly, the highest incidence of URTS occurred after rest weeks, namely the Christmas break and bye weeks (i.e., no scheduled trainings or matches); whereas URTS risk was reduced during weeks involving international travel (Hazard ratio (HR): 0.43, p<0.001)). Household illness was the strongest predictor of URTS risk; players were almost three-fold more at risk for an URTS episode when illness in the household was present (HR: 2.90, p=0.002). A non-significant, but potentially important trend for an inverse association between SIgA concentration and URTS incidence was also observed (HR: 0.99, p=0.070). CONCLUSIONS: Rest weeks were identified as periods of increased risk for URTS; while international travel did not appear to increase players risk for URTS. Incidence of household illness and SIgA concentration independently predicted URTS risk, with household illness being the strongest predictor. These findings can assist practitioners monitoring and management of athletes to potentially reduce URTS risk.


Asunto(s)
Transmisión de Enfermedad Infecciosa , Composición Familiar , Familia , Fútbol Americano , Infecciones del Sistema Respiratorio/transmisión , Adulto , Biomarcadores/metabolismo , Humanos , Hidrocortisona/metabolismo , Inmunoglobulina A Secretora/metabolismo , Estudios Longitudinales , Estudios Prospectivos , Saliva , Encuestas y Cuestionarios , Adulto Joven
14.
Fish Shellfish Immunol ; 104: 633-639, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32569712

RESUMEN

Vibriosis disease is a major constraint for sustainable molluscan aquaculture. Development of strategies to enhance disease resistance during grow out would greatly reduce stock mortality and boost production yields. In this study, New Zealand black-footed abalone (Haliotis iris) were fed a commercial diet enhanced with multi-strain probiotics (Exiguobacterium JHEb1, Vibrio JH1 and Enterococcus JHLDc) for four months, then challenged with an injection of pathogenic Vibrio splendidus. Host immune responses in haemocytes were characterized using flow cytometry by measuring total haemocyte counts (THC) and viability, degree of apoptosis, and production of reactive oxygen species (ROS) 48 h post-challenge. Probiotic-fed abalone had significantly higher survival rates compared to control animals after the bacterial challenge. Infected probiotic-fed abalone also had significantly higher haemocyte viabilities, slightly lower proportions of haemocytes undergoing early apoptosis, and lower proportions of ROS-producing haemocytes compared to infected control-fed abalone. In addition, metabolite profiles of muscle tissues generated via gas chromatography-mass spectrometry (GC-MS) delivered complimentary evidence to support a perturbed ROS-regulatory system in infected abalone through changes in key metabolites associated with glutathione biosynthesis. The results of this study provide valuable information to assist in farm management practices, leading to enhance production and sustainability of the New Zealand abalone aquaculture industry.


Asunto(s)
Gastrópodos/inmunología , Inmunidad Innata , Probióticos/metabolismo , Vibrio/fisiología , Alimentación Animal/análisis , Animales , Dieta , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Nueva Zelanda , Probióticos/administración & dosificación , Distribución Aleatoria
15.
J Fish Biol ; 96(3): 731-746, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31995234

RESUMEN

Polyinosinic:polycytidylic acid [poly (I:C)] was administered in vivo to Chinook salmon (Oncorhynchus tshawytscha) post-smolts to determine the immune responses on haematological and cellular functional parameters, including spleen (SP), head kidney (HK) and red blood cell (RBC) cytokine expression, as well as serum metabolomics. Poly (I:C) in vivo (24 h exposure) did not affect fish haematological parameters, leucocyte phagocytic activity and phagocytic index, reactive oxygen species and nitric oxide production. Gas chromatography-mass spectrometry-based metabolomics revealed that poly (I:C) significantly altered the serum biochemistry profile of 25 metabolites. Metabolites involved in the branched-chain amino acid/glutathione and transsulphuration pathways and phospholipid metabolism accumulated in poly (I:C)-treated fish, whereas those involved in the glycolytic and energy metabolism pathways were downregulated. At cytokine transcript level, poly (I:C) induced a significant upregulation of antiviral ifnγ in HK and Mx1 protein in HK, SP and RBCs. This study provides evidence for poly (I:C)-induced, immune-related biomarkers at metabolic and molecular levels in farmed O. tshawytscha in vivo. These findings provide insights into short-term effects of poly (I:C) at haematological, innate and adaptive immunity and metabolic levels, setting the stage for future studies.


Asunto(s)
Metabolismo Energético/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Sistema Inmunológico/efectos de los fármacos , Poli I-C/farmacología , Salmón/inmunología , Adyuvantes Inmunológicos/farmacología , Animales , Proteínas de Peces/genética , Riñón Cefálico/efectos de los fármacos , Leucocitos/efectos de los fármacos , Fagocitosis/efectos de los fármacos , Salmón/metabolismo
16.
Sports Med ; 50(4): 641-656, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31820376

RESUMEN

Ketone bodies (KB) provide an alternative energy source and uniquely modulate substrate metabolism during endurance exercise. Nutritional ketosis (blood KBs > 0.5 mM) can be achieved within minutes via exogenous ketone supplementation or days-to-weeks via conforming to a very low-carbohydrate, ketogenic diet (KD). In contrast to short-term (< 2 weeks) KD ingestion, chronic adherence (> 3 weeks) leads to a state of keto-adaptation. However, despite elevating blood KBs to similar concentrations, exogenous ketone supplementation and keto-adaptation are not similar metabolic states as they elicit diverse and distinct effects on substrate availability and metabolism during exercise; meaning that their influence on endurance exercise performance is different. In contrast to contemporary, high(er)-carbohydrate fuelling strategies, inducing nutritional ketosis is rarely ergogenic irrespective of origin and, in fact, can impair endurance performance. Nonetheless, exogenous ketone supplementation and keto-adaptation possess utility for select endurance events and individuals, thus warranting further research into their performance effects and potential strategies for their optimisation. It is critical, however, that future research considers the limitations of measuring blood KB concentrations and their utilisation, and assess the effect of nutritional ketosis on performance using exercise protocols reflective of real-world competition. Furthermore, to reliably assess the effects of keto-adaptation, rigorous dietary-training controls of sufficient duration should be prioritised.


Asunto(s)
Suplementos Dietéticos , Cetonas/administración & dosificación , Cetosis , Resistencia Física , Adaptación Fisiológica , Femenino , Humanos , Cuerpos Cetónicos , Masculino
17.
Eur J Sport Sci ; 20(7): 935-943, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31566098

RESUMEN

Hyperthermia stimulates endogenous carbohydrate metabolism during exercise; however, it is not known if exercise intensity impacts the metabolic effect of heat stress. In the first study of this two-part investigation, endurance-trained male cyclists performed incremental exercise assessments in 18 and 35°C (60% rH). The stimulatory effect of heat stress on carbohydrate oxidation rates was greater at high vs. moderate vs. low relative intensity (P < 0.05). In agreement, no effects of heat stress on carbohydrate oxidation rates were observed during 60-min of subsequent low-intensity cycling. In study two, endurance-trained male cyclists performed 20-min of moderate-intensity (power at the first ventilatory threshold) and 5-min of high-intensity (power at the second ventilatory threshold) cycling in 18, 28, 34, and 40°C (60% rH). At moderate-intensity, carbohydrate oxidation rates were significantly elevated by heat stress in 40°C (P < 0.05), whereas at high-intensity carbohydrate oxidation rates were significantly elevated by heat stress in 34 and 40°C (P < 0.05). This exercise intensity-mediated regulation of the effect of heat stress on carbohydrate oxidation may be partially attributable to observed plasma adrenaline responses. Our data suggest that under moderate environmental heat stress (34-35°C, 60% rH), heat stress-induced changes in CHO oxidation rates are unlikely to occur unless the relative exercise intensity is high (81 ± 8%⩒O2max), whereas under more extreme environmental heat stress (40°C, 60% rH), these changes occur at lower relative intensities (69 ± 8%⩒O2max). This provides indication of when heat stress-induced metabolic changes during exercise are likely to occur.


Asunto(s)
Ciclismo/fisiología , Metabolismo de los Hidratos de Carbono/fisiología , Ejercicio Físico/fisiología , Respuesta al Choque Térmico/fisiología , Adulto , Glucemia/análisis , Regulación de la Temperatura Corporal , Epinefrina/sangre , Calor , Humanos , Ácido Láctico/sangre , Metabolismo de los Lípidos/fisiología , Masculino , Oxidación-Reducción
18.
Eur J Appl Physiol ; 120(1): 191-202, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31729600

RESUMEN

PURPOSE: We investigated the effect of the racemic ß-hydroxybutyrate precursor, R,S-1,3-butanediol (BD), on T-cell-related cytokine gene expression within stimulated peripheral blood mononuclear cells (PBMC) following prolonged, strenuous exercise. METHODS: A repeated-measures, randomised, crossover study was conducted in nine healthy, trained male cyclists (age, 26.7 ± 5.2 years; VO2peak, 63.9 ± 2.5 mL kg-1 min-1). Participants ingested 0.35 g kg-1 of BD or placebo 30 min before and 60 min during 85 min of steady-state (SS) exercise, which preceded a ~ 30 min time-trial (TT) (7 kJ kg-1). Blood samples were collected at pre-supplement, pre-exercise, post-SS, post-TT and 1-h post-TT. Whole blood cultures were stimulated with Staphylococcal enterotoxin B (SEB) for 24 h to determine T-cell-related interleukin (IL)-4, IL-10 and interferon (IFN)-γ mRNA expression within isolated PBMCs in vitro. RESULTS: Serum cortisol, total circulating leukocyte and lymphocyte, and T-cell subset concentrations were similar between trials during exercise and recovery (all p > 0.05). BD ingestion increased T-cell-related IFN-γ mRNA expression compared with placebo throughout exercise and recovery (p = 0.011); however, IL-4 and IL-10 mRNA expression and the IFN-γ/IL-4 mRNA expression ratio were unaltered (all p > 0.05). CONCLUSION: Acute hyperketonaemia appears to transiently amplify the initiation of the pro-inflammatory T-cell-related IFN-γ response to an immune challenge in vitro during and following prolonged, strenuous exercise; suggesting enhanced type-1 T-cell immunity at the gene level.


Asunto(s)
Citocinas/metabolismo , Cetosis/sangre , Acondicionamiento Físico Humano/métodos , Linfocitos T/inmunología , Adulto , Butileno Glicoles/farmacología , Citocinas/genética , Enterotoxinas/farmacología , Humanos , Cetosis/etiología , Masculino , Monocitos/metabolismo , Linfocitos T/efectos de los fármacos
19.
Fish Shellfish Immunol ; 95: 44-80, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31604150

RESUMEN

Evaluating studies over the past almost 40 years, this review outlines the current knowledge and research gaps in the use of isolated leucocytes in salmonid immunology understanding. This contribution focuses on the techniques used to isolate salmonid immune cells and popular immunological assays. The paper also analyses the use of leucocytes to demonstrate immunomodulation following dietary manipulation, exposure to physical and chemical stressors, effects of pathogens and parasites, vaccine design and application strategies assessment. We also present findings on development of fish immune cell lines and their potential uses in aquaculture immunology. The review recovered 114 studies, where discontinuous density gradient centrifugation (DDGC) with Percoll density gradient was the most popular leucocyte isolation method. Fish head kidney (HK) and peripheral blood (PB) were the main sources of leucocytes, from rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Phagocytosis and respiratory burst were the most popular immunological assays. Studies used isolated leucocytes to demonstrate that dietary manipulations enhance fish immunity, while chemical and physical stressors suppress immunity. In addition, parasites, and microbial pathogens depress fish innate immunity and induce pro-inflammatory cytokine gene transcripts production, while vaccines enhance immunity. This review found 10 developed salmonid cell lines, mainly from S. salar and O. mykiss HK tissue, which require fish euthanisation to isolate. In the face of high costs involved with density gradient reagents, the application of hypotonic lysis in conjunction with mico-volume blood methods can potentially reduce research costs, time, and using nonlethal and ethically flexible approaches. Since the targeted literature review for this study retrieved no metabolomics study of leucocytes, indicates that this approach, together with traditional technics and novel flow cytometry could help open new opportunities for in vitro studies in aquaculture immunology and vaccinology.


Asunto(s)
Riñón Cefálico/inmunología , Leucocitos/inmunología , Tejido Linfoide/inmunología , Oncorhynchus mykiss/inmunología , Salmo salar/inmunología , Animales , Acuicultura , Línea Celular , Centrifugación por Gradiente de Densidad , Dieta/veterinaria , Citometría de Flujo , Riñón Cefálico/citología , Técnicas Inmunológicas , Tejido Linfoide/citología , Fagocitosis
20.
Cancers (Basel) ; 11(9)2019 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-31500349

RESUMEN

Our recent publications showed that multidrug resistance protein 2 (MRP2, encoded by the ABCC2 gene) conferred oxaliplatin resistance in human liver cancer HepG2 cells. However, the contribution of MRP2 to oxaliplatin resistance remains unclear in colorectal and pancreatic cancer lines. We investigated the effects of silencing MRP2 by siRNA on oxaliplatin accumulation and sensitivity in human colorectal cancer Caco-2 cells and pancreatic cancer PANC-1 cells. We characterized the effects of oxaliplatin on MRP2 ATPase activities using membrane vesicles. Over-expression of MRP2 (endogenously in Caco-2 and PANC-1 cells) was associated with decreased oxaliplatin accumulation and cytotoxicity, but those deficits were reversed by inhibition of MRP2 with myricetin or siRNA knockdown. Silencing MRP2 by siRNA increased oxaliplatin-induced apoptotic rate in Caco-2 and PANC-1 cells. Oxaliplatin stimulated MRP2 ATPase activity with a concentration needed to reach 50% of the maximal stimulation (EC50) value of 8.3 ± 0.7 µM and Hill slope 2.7. In conclusion, oxaliplatin is a substrate of MRP2 with possibly two binding sites, and silencing MRP2 increased oxaliplatin accumulation and cytotoxicity in two widely available gastrointestinal tumour lines (PANC-1 and Caco-2).

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