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1.
Int J Sport Nutr Exerc Metab ; 31(4): 314-320, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34030124

RESUMEN

Gastrointestinal disturbances are one of the most common issues for endurance athletes during training and competition in the heat. The relationship between typical dietary intake or nutritional interventions and perturbations in or maintenance of gut integrity is unclear. Twelve well-trained male endurance athletes (peak oxygen consumption = 61.4 ± 7.0 ml·kg-1·min-1) completed two trials in a randomized order in 35 °C (heat) and 21 °C (thermoneutral) conditions and kept a detailed nutritional diary for eight consecutive days between the two trials. The treadmill running trials consisted of 15 min at 60% peak oxygen consumption, 15 min at 75% peak oxygen consumption, followed by 8 × 1-min high-intensity efforts. Venous blood samples were taken at the baseline, at the end of each of the three exercise stages, and 1 hr postexercise to measure gut integrity and the permeability biomarker concentration for intestinal fatty-acid-binding protein, lipopolysaccharide, and lipopolysaccharide-binding protein. The runners self-reported gut symptoms 1 hr postexercise and 3 days postexercise. The heat condition induced large (45-370%) increases in intestinal fatty-acid-binding protein, lipopolysaccharide-binding protein, and lipopolysaccharide concentrations compared with the baseline, but induced mild gastrointestinal symptoms. Carbohydrate and polyunsaturated fat intake 24 hr preexercise were associated with less lipopolysaccharide translocation. Protein, carbohydrate, total fat, and polyunsaturated fat intake (8 days) were positively associated with the percentage increase of intestinal fatty-acid-binding protein in both conditions (range of correlations, 95% confidence interval = .62-.93 [.02, .98]). Typical nutrition intake partly explained increases in biomarkers and the attenuation of symptoms induced by moderate- and high-intensity exercise under both heat and thermoneutral conditions.


Asunto(s)
Ingestión de Alimentos , Tracto Gastrointestinal/fisiología , Calor , Esfuerzo Físico/fisiología , Carrera/fisiología , Adulto , Biomarcadores/sangre , Intervalos de Confianza , Estudios Cruzados , Registros de Dieta , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Ingestión de Energía , Proteínas de Unión a Ácidos Grasos/sangre , Ácidos Grasos Insaturados/administración & dosificación , Humanos , Lipopolisacáridos/sangre , Masculino , Consumo de Oxígeno , Acondicionamiento Físico Humano/fisiología , Resistencia Física , Fenómenos Fisiológicos en la Nutrición Deportiva , Factores de Tiempo
2.
Hum Psychopharmacol ; 34(4): e2700, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31173409

RESUMEN

OBJECTIVE: Modafinil is a psychostimulant that has been shown to enhance cognitive and physical performance. Given its long half-life, it may provide operational advantages if it can improve tolerance to the deleterious effects of prolonged mental exertion. METHODS: Physically active males (n = 13, 23 ± 4 years, peak oxygen consumption 45.3 ± 3.2 ml kg-1  min-1 ) took part in a placebo controlled, double-blind randomised crossover study to investigate if modafinil could improve cognitive and physical performance following a prolonged period of mental exertion. RESULTS: Overall modafinil improved performance on a task of executive function over time (p = .023; η2  = 0.376) but did not improve subsequent physical endurance performance (mean difference 2.3 ± 11.5%, p = .50), despite improvement in 10 out of the 13 participants. Task demand was reported as lower with modafinil, although perceptual measures of fatigue and motivation did not consistently improve. Heart rate during submaximal exercise was higher (134 ± 11 vs. 119 ± 14 bpm, p < .001), and sleep was reduced (5.5 ± 1.4 vs. 7.5 ± 1.4 hr, p < .001) and less efficient (64 ± 13 vs. 83 ± 9%, p < .001) compared with placebo. CONCLUSIONS: Operationally, modafinil may offer advantages given the established longer half-life than other psychostimulants, despite the variable response. The impact of higher heart rates and disrupted sleep on performance must also be considered.


Asunto(s)
Cognición/efectos de los fármacos , Modafinilo/farmacología , Esfuerzo Físico/fisiología , Rendimiento Físico Funcional , Adulto , Estudios Cruzados , Método Doble Ciego , Humanos , Masculino , Modafinilo/efectos adversos
3.
Lancet ; 385 Suppl 1: S60, 2015 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-26312882

RESUMEN

BACKGROUND: Necrotising fasciitis due to invasive group A streptococcus (iGAS) is frequently associated with type emm1 isolates, with an attendant mortality of 40%. Some cases occur in previously healthy individuals with a history of upper respiratory tract infection, soft tissue contusion, and no obvious portal of entry. Using a new model of mild contusion injury, we set out to determine the effect of contusion on iGAS bacterial burden, phenotype, and host cytokine response. METHODS: A new model of mild contusion was developed using a weight drop device and characterised in two strains of mice, CD1 and FVB/n. The effect of contusion on emm1 iGAS infection was assessed in three murine models of infection: lower respiratory tract (intranasal challenge of 1 × 10(7) colony forming units [CFU] per mouse), intravenous (1 × 10(7)· per mouse via the lateral tail vein), and muscle (1 × 10(8) CFU per mouse intramuscularly) at three timepoints after injury (24, 48, and 72 h). Bacterial burden, host cytokine response, and histological changes were analysed. Further molecular work was performed to assess the change in bacterial morphology observed after contusion injury in the muscle model. Mann-Whitney U test was used to compare differences in bacterial burden and cytokine responses between trauma and control groups. FINDINGS: Application of a force of 15·7 mJ resulted in histological changes in muscle consistent with mild trauma with no evidence of overlying skin injury, no bony injury, and minimum cytokine response. Contusion to soft tissue had no effect on bacterial burden or cytokine response in a mouse model of systemic infection (after intravenous inoculation) at three timepoints. Despite bacteraemia, specific seeding of the contused tissue did not occur in this model. By contrast, blunt contusion affected progression of a subsequent local GAS muscle infection and increased dissemination to blood in the lower respiratory tract infection model. Specifically, contusion increased emm1 GAS dissemination locally to draining lymph nodes (controls median 183 CFU per node [IQR 8-5800] vs trauma group 20 000 [1875-601 250]). Dissemination to lymph node was linked to a phenotypic change in bacterial capsule morphology. This phenotypic change was stable despite passage, consistent with a genetic change, and was associated with an increase in bacterial hyaluronan production (mucoid colonies 200 µg per CFU and no detectable capsule production in the non-mucoid colonies). INTERPRETATION: We found that non-penetrating trauma was associated with an enhanced susceptibility to invasive GAS disease. This model of mild contusion did not provide a focus for initiation or seeding of bacteraemic infection but instead provided an environment that determined the phenotype of the bacteria and enhanced local dissemination after iGAS infection at the same site. The environmental and genetic cues underlying dissemination are the subject of continuing research. FUNDING: Royal Army Medical Corps, Surgeon General's Research Strategy Group, Ministry of Defence.

4.
Sports Med ; 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38609697

RESUMEN

OBJECTIVES: The aim of this study was to compare the incidence, severity, and burden of injury in starting and replacement players from professional men's teams of five rugby unions. METHODS: Match injuries of greater than 24 h time-loss (including data on the severity, match quarter, event, body region) and player minutes of match exposure data were collated for all starting and replacement players in the men's English Premiership, Welsh Pro14 (both 2016/17-2018/19 seasons), and Australian, New Zealand, and South African Super Rugby (all 2016-2018 seasons) teams. Injury incidences and mean injury burden (incidence × days missed) were calculated, and rate ratios (RRs) (95% confidence intervals [CIs]) were used to compare injury incidence and burden between starting (reference group) and replacement players. RESULTS: Overall injury incidence was not different between starters and replacements for all injuries (RR = 0.98, 95% CI 0.88-1.10), nor for concussions (RR = 0.85; 95% CI 0.66-1.11). Mean injury burden was higher for replacement players (RR = 1.31, 95% CI 1.17-1.46). Replacement injury incidence was lower than the starters in the third (RR = 0.68, 95% CI 0.51-0.92) and fourth (RR = 0.78, 95% CI 0.67-0.92) match quarters. Injury incidence was not different between starters and replacements for any match event or body region, but compared with starters, replacements' injury burden was higher in lower limbs (RR = 1.24, 95% CI 1.05-1.46) and in the tackled player (RR = 1.30, 95% CI 1.01-1.66). CONCLUSION: This study demonstrated a lower injury incidence in replacement players compared with starters in the second half of matches, with a higher injury burden for replacement players due to higher mean injury severity.

5.
Integr Pharm Res Pract ; 11: 33-45, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35117984

RESUMEN

BACKGROUND: Lack of teamwork is the bane of weak and ineffective health care systems in many countries. This study examined the perceptions and lived experiences of pharmacists working in a Nigerian government-owned (public) multispecialty tertiary hospital regarding teamwork in their workplace. METHODS: A sequential explanatory mixed methods study using phenomenological approach of inquiry, was conducted among pharmacists with experience in multidisciplinary health care provision in a public tertiary hospital in Nigeria. Questionnaires with 16 close-ended questions based on a Likert scale, which scored from strongly disagree (1) to strongly agree (5), were administered. The mean (M) scores were determined using SPSS Version 20; M ≥ 3.00 indicated agree, while M < 3.00 disagree. Subsequently, focus group discussions were conducted, and the audio recorded responses transcribed and subjected to thematic analysis using NVivo 11. RESULTS: Some participants (50%) had worked for 5-10 years in the hospital's Department of Pharmacy, 25% (11-20 years), and 16.7% (21-30 years). Participants agreed that effective teamwork leads to positive patient outcomes (M = 3.67) and is in the public's interest (M = 4.25). However, they disagreed that their workplace supports teamwork (M = 2.33), effective interprofessional collaborative practices exist in the hospital (M = 1.08), and their remuneration reflects their worth to the organization (M = 2.33). Doctors' dominance and claim of ownership of patients, allied professionals' attitudes and ignorance of pharmacists' roles, salary disparity, poor communication, and defective leadership style among others were identified as impediments to teamwork. CONCLUSION: The hospital pharmacists demonstrated positive disposition towards teamwork, and agreed that effective teamwork would improve health care delivery. However, they identified some factors that hinder interprofessional teamwork in the hospital. Principles and practices of teamwork should be incorporated into the curriculum of each discipline; interdisciplinary collaborative practices, health system structure, institutional policies and leadership should be strengthened to enhance teamwork.

6.
J Sci Med Sport ; 24(12): 1204-1210, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34247976

RESUMEN

OBJECTIVES: Current off-field concussion screening instruments have sub-optimal accuracy and additional testing domains may be necessary to detect the full spectrum of concussion presentations. This study aimed to determine if additional cognitive tests add utility to off-field screening for sport-related concussion. DESIGN: Reproducibility and diagnostic accuracy cohort studies were performed in the 2017 and 2018 seasons of the Super Rugby competition, conducted in Argentina, Australia, Japan, New Zealand, and South Africa. METHODS: Abridged versions of Stroop (score, time), Spatial Memory (score, failed trials), and Trail Making Trial-B (time, errors) cognitive tests, modified for off-field use, were examined. Players performed baseline testing prior to each season. Cases undergoing off-field screening as part of the World Rugby Head Injury Assessment Process underwent evaluation with the same cognitive tests during competition matches. Agreement between repeated pre-season baseline measurements, and the diagnostic accuracy of off-field testing against a clinical reference standard of concussion, was evaluated. RESULTS: Data were available for repeated preseason baseline testing in 644 players, and 100 cases undergoing off-field concussion screening. There was little individual agreement across pre-season baseline assessments for all tests (Lin's correlation and Gwets AC1 coefficients ranging between 0.2 and 0.3). There was significantly worse performance for the time taken to complete the modified Stroop Test in concussed players undergoing off-field screening, compared to non-concussed players (median time 21.1 v 18.4 s, p < 0.01; area under the receiver operating characteristic curve 0.7 (95% CI 0.5-0.8)). Other cognitive measures did not discriminate between injured and un-injured players, with no-statistically significant differences in distribution medians (p = 0.6-0.9) and AUROC values close to 0.5. CONCLUSIONS: The time taken to perform a modified Stroop Test may provide additional diagnostic accuracy if added to current off-field concussion screening tools. Abridged Spatial Memory and Trail Making Trial-B tests did not discriminate between concussed and non-concussed players.


Asunto(s)
Traumatismos en Atletas/diagnóstico , Conmoción Encefálica/diagnóstico , Fútbol Americano/lesiones , Tamizaje Masivo/normas , Pruebas Neuropsicológicas/normas , Adolescente , Adulto , Estudios de Cohortes , Humanos , Masculino , Reproducibilidad de los Resultados , Adulto Joven
7.
J Neurooncol ; 96(2): 181-9, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19847623

RESUMEN

Local recurrence continues to limit survival in medulloblastoma patients, largely related to the persistence of invasive cells at the site of tumour resection and leptomeningeal dissemination. Given the relative dearth of understanding of causative mechanisms behind the invasiveness of medulloblastomas, and a general lack of validated in vitro models with which to study them, our objectives were (1) to obtain quantitative data on the invasiveness of five distinct medulloblastoma cell lines within a 3-dimensional in vitro collagen-based model; and (2) to characterize some of the mechanisms behind invasion, specifically striving to identify proteolytic processes that occur as medulloblastoma cells disrupt and thereby invade the normal tissue surrounding them, and specific inhibitors of these proteolytic enzymes. Five different medulloblastoma cell lines (UW228-1, 2 and 3; Daoy, and Madsen) were implanted onto a 3-dimensional, type I collagen gel assay to assess tumour invasion distance and mean doubling time over 5 days. Proteolytic activity was assessed against collagen types I and IV by measuring the degradation of 3H-collagen I and IV to products soluble in 100% w/v trichloroacetic acid; and general (neutral) proteolytic activity evaluated by measuring the degradation of 3H-albumin. In other experiments, cells were pre-exposed to a variety of protease inhibitors, including inhibitors of metalloproteinases and cysteine, serine and aspartic proteases, and then plated to identify any inhibition of invasion. Inter-group differences in mean invasion distance were assessed by means of Student's t-tests for non-paired subjects, with P < 0.05 set as the threshold for statistical significance. For the inhibitor studies, an inhibition index, called the inhibitory concentration 50, IC-50, was calculated by performing a regression analysis for each inhibitor tested over a range of concentrations, for each cell line. Within hours of implantation, individual cells readily detached from the surface of the cell aggregates and invaded the collagen matrix, to distances of up to 1,200 mum and at rates of up to 300-mum per day; the UW228-1 cell line clearly was less invasive than the other four cell lines. Proteolytic activity was identified against collagen type I, but not against collagen type IV or albumin; but there was no apparent correlation between invasion distance and either cell doubling time or the amount of collagen type I proteolytic activity. Both metalloproteinase inhibitors suppressed tumour invasion, as did one of two cysteine protease inhibitors; but there was no tumour suppression with either serine or aspartic protease inhibition. MMP-1 and 2, and TIMP-1 and 2 all were detectable by Western blot analysis. Medulloblastoma cell invasiveness within the 3-dimensional model used here appears to depend upon a combination of metalloproteinase and cysteine protease activity, a finding that may suggest areas for potential future clinical investigation and therapy.


Asunto(s)
Colágeno/metabolismo , Meduloblastoma/enzimología , Meduloblastoma/fisiopatología , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Colágeno/efectos de los fármacos , Colágeno/ultraestructura , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Matriz Extracelular/metabolismo , Matriz Extracelular/ultraestructura , Humanos , Metaloproteinasa 1 de la Matriz/metabolismo , Microscopía Electrónica de Rastreo/métodos , Factores de Tiempo
8.
Eur J Appl Physiol ; 109(2): 221-31, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20058020

RESUMEN

In order to quantify the seasonal variability of haemoglobin mass (Hb(mass)) in cyclists during a competitive season, and investigate whether variability is associated with changes in training load or performance, Hb(mass) was measured in 10 internationally competitive female road cyclists approximately once per month for 2-10 months via CO-rebreathing. Power meters were used to quantify daily load (Training Stress Scores) during training and racing, from which cumulative training load units for 7, 14, 28 and 42 day were calculated. Maximal mean power (MMP) for 1, 4, 10 and 25 min, performed during training or racing was used as a surrogate for performance. The relationship between changes in training load (%DeltaTraining) and changes in Hb(mass) (%DeltaHb(mass)), and between %DeltaHb(mass) and changes in MMP (%DeltaMMP) was established via regression analysis. Individual coefficients of variation (CV) in Hb(mass) ranged from 2.0 to 4.4%. The weighted mean CV in Hb(mass) was 3.3% (90% Confidence Limits: 2.9-3.8%) or 23 g over the average 6.6 +/- 2.3 month monitoring period. The effect of %DeltaTraining on %DeltaHb(mass) was small for 7 and 14 day (r = 0.22 and 0.29), moderate for 42 day (r = 0.35) and large for 28 day (r = 0.56). The regression slope was greatest for 42 day, with a 10% change in training associated with a approximately 1% change in Hb(mass). The relationship between %DeltaHb(mass) and %DeltaMMP was approximately 0.5:1 for MMP(1min),(10 min) and (25 min) and approximately 1:1 for MMP(4 min), respectively. Hb(mass) varies by approximately 3% in female cyclists during a competitive season. Some of the variation may be related to oscillations in chronic training load.


Asunto(s)
Atletas , Ciclismo/fisiología , Hemoglobinas/metabolismo , Estaciones del Año , Adulto , Femenino , Humanos , Esfuerzo Físico , Adulto Joven
9.
Can J Neurol Sci ; 36(5): 631-7, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19831134

RESUMEN

OBJECTIVES: Surgical resection and adjuvant radiation are mainstays of medulloblastoma (MB) patient management. We utilized a novel 3-dimensional assay to identify how (a) radiation, (b) excision of the primary tumour aggregate, and (c) both treatments combined influence MB cell invasiveness. METHODS: Five MB cell lines (UW228-1, 2 and 3; Daoy, and Madsen) were implanted onto a 3-dimensional, type I collagen gel assay to assess tumour invasion distance over five days, in response to (1) needle-assisted excision of the central cell aggregate; (2) pre-exposure to single-dose and fractionated dose irradiation in doses from 6-25 and 8-24 Gy, respectively; and (3) excision plus either single-dose or fractionated radiation. RESULTS: Within hours, individual MB cells detached from the surface of the cell aggregates and invaded the collagen matrix, to distances up to 1200 microm and at rates up to 300 microm daily. The UW228-1 cell line was less invasive than the other cell lines and was dropped from further analysis. In the four remaining lines, a dose-dependent decline in tumour invasiveness was identified, both for single-dose and fractionated radiation, which achieved statistically decreased invasion distances at higher doses, especially of fractionated irradiation. Excision of the central tumour aggregate tended towards exerting a late effect on cell invasion, but exerted no significant influence on the radio-sensitivity of residual cells. CONCLUSIONS: Both single-dose and fractionated dose irradiation appear to inhibit MB cell invasiveness in a dose-dependent manner, whereas excision of the central cell aggregate exerts no effect on residual invading cells.


Asunto(s)
Meduloblastoma/cirugía , Meduloblastoma/terapia , Modelos Biológicos , Invasividad Neoplásica/patología , Línea Celular Tumoral , Supervivencia Celular , Estructuras Celulares/patología , Relación Dosis-Respuesta en la Radiación , Matriz Extracelular/metabolismo , Matriz Extracelular/patología , Matriz Extracelular/efectos de la radiación , Humanos , Meduloblastoma/patología , Trasplante de Neoplasias/métodos , Tolerancia a Radiación , Factores de Tiempo
10.
Expert Rev Proteomics ; 5(5): 663-78, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18937557

RESUMEN

Proteomics is a data-rich discipline that makes extensive use of separation tools, mass spectrometry and bioinformatics to analyze and interpret the features and dynamics of the proteome. A major challenge for the field is how proteomics data can be stored and managed, such that data become permanent and can be mined with current and future tools. This article details our experience in the development of a commercial proteomic information management system. We identify the challenges faced in data acquisition, workflow management, data permanence, security, data interpretation and analysis, as well as the solutions implemented to address these issues. We finally provide a perspective on data management in proteomics and the implications for academic and industry-based researchers working in this field.


Asunto(s)
Bases de Datos de Proteínas , Almacenamiento y Recuperación de la Información/métodos , Proteómica/métodos , Programas Informáticos , Interfaz Usuario-Computador
11.
Sports Med Open ; 4(1): 54, 2018 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-30523560

RESUMEN

In the original article [1] reference was made to the Hawk-Eye system having been used as the sideline operating system during the 2015 season.

12.
J Sports Med Phys Fitness ; 58(10): 1490-1496, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28597617

RESUMEN

BACKGROUND: Given the likely influence that high training loads, contact-induced hemolysis and female-specific requirements have on the incidence of iron deficiency, characterizing the direction and magnitude of fluctuations in iron status over an international season is important for managing player health and physical performance in rugby sevens. METHODS: Australian national male (N.=27) and female (N.=23) rugby sevens players undertook blood tests at pre-season, mid-season, and end-season. Hemoglobin (Hb), hematocrit (Hct), ferritin, transferrin and transferrin saturation were quantified. Female athletes also reported oral contraceptive use and a subset (N.=7) provided 7-day food diaries to quantify iron intake. RESULTS: Male players typically had a three-fold higher ferritin concentration than females. Pre-season ferritin concentrations in male (151±66 µg/L) and female (51±24 µg/L) players declined substantially (~20%) by mid-season but recovered by end-season. Over the season 23% of female players were classified as iron deficient (ferritin <30 µg/L) and prescribed supplementation. The greatest incidence of iron deficiency in female players occurred mid-season (30%). Oral contraception and dietary iron intake had an unclear influence on female players' ferritin concentration, while age was largely positively correlated (r=0.66±~0.33). CONCLUSIONS: Given the relatively low ferritin concentrations evident in female rugby sevens players, and the potential for a further decline midway through a season when physical load may be at its highest, 6-monthly hematological reviews are suggested in combination with dietary management. Annual screening may be beneficial for male players, with further monitoring only when clinically indicated.


Asunto(s)
Fútbol Americano , Hierro/sangre , Fenómenos Fisiológicos en la Nutrición Deportiva , Adulto , Atletas , Australia , Femenino , Ferritinas/análisis , Hematócrito , Hemoglobinas/análisis , Humanos , Deficiencias de Hierro , Estudios Longitudinales , Masculino , Factores de Tiempo , Transferrina/análisis , Adulto Joven
13.
Sports Med Open ; 4(1): 20, 2018 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-29797099

RESUMEN

BACKGROUND: Sideline video review has been increasingly used to evaluate risk of concussive injury during match play of a number of collision sports, with the view to reducing the incidence of match play concussion injuries. The purpose of this study was to evaluate the effectiveness of sideline video review for identifying and evaluating head impact events in Rugby Union. METHODS: All Australian teams' 2015 Super Rugby season matches were studied. Meaningful head impact events (HIEs) were identified, comprising events identified and acted upon during matches and events identified through a post-season retrospective review. Video footage of each HIE was coded by two experienced independent sports medicine clinicians to evaluate management decisions made by match-day (MDD) and team doctors (TD). HIE incidences for matches with and without sideline video were compared, and the agreement between game-day video interpretation and the independent clinician opinion calculated. RESULTS: Seventy HIEs were identified in 83 matches (47 identified during matches and 23 identified post-season), equating to 42.5 HIEs per 1000 player match hours. When video review was available, an unnoticed HIE occurred once every 4.3 matches, compared to once every 2.3 matches when the sideline video review was unavailable. Of the 47 identified in-match HIEs evaluated by TD and MDD during the season, 18 resulted in an immediate and permanent removal, 28 resulted in temporary removal for an off-field assessment, and one resulted in the player continuing the game. Game-day head injury assessment process video decisions agreed with the independent clinician view in 72% of cases, κ = 0.49 (95% CI 0.38-0.59, weak agreement). CONCLUSIONS: These findings suggest that access to sideline video review is an important supplementary component to identify potential concussions; however, there is a critical need for improved systems and processes to reduce the likelihood of missing an incident.

14.
Hepatobiliary Surg Nutr ; 5(3): 204-8, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27275461

RESUMEN

BACKGROUND: Understanding the prognosis of hepatocellular carcinoma (HCC) informs plans for care. Tumor morphology and molecular markers have been correlated with outcomes. Three-dimensional tissue culture (3DTC) allows for direct in vitro measurement of a tumor's ability to grow and metastasize. The impact of chemotherapeutic agents, alone or in combinations, may also be measured. METHODS: All patients with a presumed diagnosis of HCC were eligible for this study including those undergoing resection, chemoembolization and transplantation. Concomitant diseases and outcomes were recorded. One mm(3) HCC specimens were grown in multiwell plates containing gel media, without and with chemotherapeutic agents. RESULTS: Tumors were sampled from 17 patients. Only 13 had HCC, all of whom had liver transplantation. Of the confirmed HCC patients, 6 (46%) are alive and disease free 82 months following transplantation, 1 (7%) is alive with recurrence of disease and 6 (46%) died, with a mean survival of 12 months post liver transplant. Ten of thirteen 3DTC samples grew, having an average migration distance of 108.3µm in the first 24 hours. Two of three patients who had prior chemoembolization had successful 3DTC. Migration distances (µm) were 188.8±104.3, 104.5±111.7 and 39.6±32.4 for tumors categorized as high, intermediate and low grade, respectively. Tumor migration was inhibited by irinotecan, paclitaxel and docetaxel (-68%±7%, -61%±19% and -60%±21%, respectively) whereas the effect was variable with 5 fluorouracil (5FU) and doxorubicin (-12%±51% and 9%±76%, respectively). CONCLUSIONS: It is feasible to grow tissue from HCC in 3DTC to study the tumor's capacity to grow and migrate and its responsiveness to commonly used chemotherapeutic protocols.

15.
PLoS One ; 10(12): e0143028, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26629912

RESUMEN

PURPOSE: The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour. METHODS: Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (<1000 m, 1000-2000, 2000-3000 and >3000 m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin. RESULTS: Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level. CONCLUSION: A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.


Asunto(s)
Altitud , Ciclismo/fisiología , Atletas , Frecuencia Cardíaca , Humanos , Lagos , Masculino
16.
Med Sci Sports Exerc ; 34(3): 411-7, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11880803

RESUMEN

PURPOSE: The aim of this study was to investigate the relationships between latent viral shedding of Epstein-Barr virus (EBV) in saliva, upper-respiratory illness, and mucosal immune suppression in a cohort of highly trained swimmers undertaking intensive training. METHODS: Saliva was collected before selected training sessions from 14 elite male swimmers during a 30-d period of intensive training. Prior infection with EBV was determined by EBV antibody serology. Salivary IgA concentrations were measured by enzyme linked immunosorbent assay (ELISA), and EBV viral shedding (EBV-DNA) was detected by polymerase chain reaction (PCR). Symptoms of upper-respiratory illness were recorded daily. RESULTS: Eleven swimmers (79%) were seropositive for prior EBV infection. Seven EBV seropositive swimmers (64%) had EBV-DNA detected during the study period. Upper-respiratory symptoms (URS) were reported in six of seven swimmers in whom EBV-DNA was detected and in three of four swimmers with no EBV-DNA detection. No URS were reported in the EBV seronegative swimmers. There was a statistically significant relationship between EBV serology status and URS (P = 0.027). EBV-DNA was detected in saliva before the appearance of URS. Salivary IgA levels were significantly lower immediately before the URS (P = 0.01) compared with subsequent peak IgA levels and declined to pre-URS levels on average 11 d after the first appearance of URS. CONCLUSIONS: The time course of appearance of EBV-DNA in relation to URS suggests latent viral EBV shedding may be a contributing factor in the URS. The low levels of salivary IgA detected before the URS indicated transient mucosal immune suppression in the study cohort. The viral shedding may alternatively be a reflection of the altered immune control mechanisms that occur in response to intensive exercise and unrelated to the URS.


Asunto(s)
Herpesvirus Humano 4/crecimiento & desarrollo , Infecciones del Sistema Respiratorio/virología , Saliva/virología , Natación , Activación Viral , Adolescente , Adulto , ADN Viral/análisis , Humanos , Inmunidad Mucosa , Inmunoglobulina A/análisis , Infecciones del Sistema Respiratorio/inmunología , Esparcimiento de Virus
18.
Int J Sports Physiol Perform ; 2(1): 58-71, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19255455

RESUMEN

PURPOSE: To quantify the fluid and food consumed during a men's and women's professional road-cycling tour. METHODS: Eight men (age 25 +/- 5 y, body mass 71.4 +/- 7.4 kg, and height 177.4 +/- 4.5 cm) and 6 women (age 26 +/- 4 y, body mass 62.5 +/- 5.6 kg, and height 170.4 +/- 5.2 cm) of the Australian Institute of Sport Road Cycling squads participated in the study. The men competed in the 6-d Tour Down Under (Adelaide, Australia), and the women, in the 10-d Tour De L'Aude (Aude, France). Body mass was recorded before and immediately after the race. Cyclists recalled the number of water bottles and amount of food they had consumed. RESULTS: Men and women recorded body-mass losses of approximately 2 kg (2.8% body mass) and 1.5 kg (2.6% body mass), respectively, per stage during the long road races. Men had an average fluid intake of 1.0 L/h, whereas women only consumed on average 0.4 L/h. In addition, men consumed CHO at the rate suggested by dietitians (average CHO intake of 48 g/h), but again the women failed to reach recommendations, with an average intake of approximately 21 g/h during a road stage. CONCLUSIONS: Men appeared to drink and eat during racing in accordance with current nutritional recommendations, but women failed to reach these guidelines. Both men and women finished their races with a body-mass loss of approximately 2.6% to 2.8%. Further research is required to determine the impact of this loss on road-cycling performance and thermoregulation.


Asunto(s)
Adaptación Fisiológica , Ciclismo/fisiología , Deshidratación , Ingestión de Alimentos/fisiología , Conducta Alimentaria/fisiología , Estado Nutricional , Adulto , Análisis de Varianza , Índice de Masa Corporal , Ingestión de Líquidos/fisiología , Metabolismo Energético , Femenino , Humanos , Masculino
19.
Eur J Appl Physiol ; 95(5-6): 529-36, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16151832

RESUMEN

Little information exists on the power output demands of competitive women's road cycle racing. The purpose of our investigation was to document the power output generated by elite female road cyclists who achieved success in FLAT and HILLY World Cup races. Power output data were collected from 27 top-20 World Cup finishes (19 FLAT and 8 HILLY) achieved by 15 nationally ranked cyclists (mean +/- SD; age: 24.1+/-4.0 years; body mass: 57.9+/-3.6 kg; height: 168.7+/-5.6 cm; VO2max 63.6+/-2.4 mL kg(-1) min(-1); peak power during graded exercise test (GXT(peak power)): 310+/-25 W). The GXT determined GXT(peak power), VO2peak lactate threshold (LT) and anaerobic threshold (AT). Bicycles were fitted with SRM powermeters, which recorded power (W), cadence (rpm), distance (km) and speed (km h(-1)). Racing data were analysed to establish time in power output and metabolic threshold bands and maximal mean power (MMP) over different durations. When compared to HILLY, FLAT were raced at a similar cadence (75+/-8 vs. 75+/-4 rpm, P=0.93) but higher speed (37.6+/-2.6 vs. 33.9+/-2.7 km h(-1), P=0.008) and power output (192+/-21 vs. 169+/-17 W, P=0.04; 3.3+/-0.3 vs. 3.0+/-0.4 W kg(-1), P=0.04). During FLAT races, riders spent significantly more time above 500 W, while greater race time was spent between 100 and 300 W (LT-AT) for HILLY races, with higher MMPs for 180-300 s. Racing terrain influenced the power output profiles of our internationally competitive female road cyclists. These data are the first to define the unique power output requirements associated with placing well in both flat and hilly women's World Cup cycling events.


Asunto(s)
Ciclismo/fisiología , Adulto , Umbral Anaerobio , Conducta Competitiva/fisiología , Femenino , Geografía , Humanos , Ácido Láctico/sangre , Poder Psicológico , Ventilación Pulmonar
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