Efectos de una intervención nutricional personalizada a largo plazo sobre los hábitos alimentarios de jugadores profesionales de baloncesto y su influencia en la percepción del esfuerzo y la fatiga

El presente trabajo consistió en el desarrollo de una intervención nutricional a largo plazo llevada a cabo con jugadores profesionales de baloncesto, en función al cumplimiento de las recomendaciones nutricionales, con los siguientes dos objetivos: 1) valorar los cambios que dicha intervención produce sobre las prácticas nutricionales diarias de estos deportistas y 2) conocer la influencia de las modificaciones nutricionales producidas sobre la tasa de percepción del esfuerzo por sesión (RPE-Sesión) y la fatiga, a lo largo de una temporada competitiva, tanto para entrenamientos como partidos oficiales. Los objetivos del estudio se fundamentan en: 1) la numerosa evidencia científica que muestra la inadecuación de los hábitos nutricionales de los jugadores de baloncesto y otros deportistas respecto a las recomendaciones nutricionales; 2) el hecho ampliamente reconocido en la literatura especializada de que una ingesta nutricional óptima permite maximizar el rendimiento deportivo (a nivel físico y cognitivo), promoviendo una rápida recuperación y disminuyendo el riesgo de enfermedades y lesiones deportivas. No obstante, pocos estudios han llevado a cabo una intervención nutricional a largo plazo para mejorar los hábitos alimentarios de los deportistas y ninguno de ellos fue realizado con jugadores de baloncesto; 3) la elevada correlación entre la percepción del esfuerzo (RPE) y variables fisiológicas relacionadas al desarrollo de un ejercicio (por ej.: frecuencia cardíaca, consumo máximo de oxígeno o lactato sanguíneo) y los múltiples estudios que muestran la atenuación de la RPE durante la realización del ejercicio mediante una ingesta puntual de nutrientes, (especialmente de hidratos de carbono) aunque ninguno fue desarrollado en baloncesto; 4) el estudio incipiente de la relación entre la ingesta nutricional y la RPE-Sesión, siendo éste un método validado en baloncesto y otros deportes de equipo como indicador de la carga de trabajo interna, el rendimiento deportivo y la intensidad del ejercicio realizado; 5) el hecho de que la fatiga constituye uno de los principales factores influyentes en la percepción del esfuerzo y puede ser retrasada y/o atenuada mediante la ingesta de carbohidratos, pudiendo disminuir consecuentemente la RPE-Sesión y la carga interna del esfuerzo físico, potenciando el rendimiento deportivo y las adaptaciones inducidas por el entrenamiento; 6) la reducida evidencia acerca del comportamiento de la RPE-Sesión ante la modificación de la ingesta de nutrientes, encontrándose sólo un estudio llevado a cabo en baloncesto y 7) la ausencia de investigaciones acerca de la influencia que puede tener la mejora del patrón nutricional de los jugadores sobre la RPE-Sesión y la fatiga, desconociéndose si la adecuación de los hábitos nutricionales conduce a una disminución de estas variables en el largo plazo para todos los entrenamientos y partidos oficiales a nivel profesional. Por todo esto, este trabajo comienza con una introducción que presenta el marco teórico de la importancia y función de la nutrición en el deporte, así como de las recomendaciones nutricionales actuales a nivel general y para baloncesto. Además, se describen las intervenciones nutricionales llevadas a cabo previamente con otros deportistas y las consecuentes modificaciones sobre el patrón alimentario, coincidiendo este aspecto con el primer objetivo del presente estudio. Posteriormente, se analiza la RPE, la RPE-Sesión y la fatiga, focalizando el estudio en la relación de dichas variables con la carga de trabajo físico, la intensidad del entrenamiento, el rendimiento deportivo y la recuperación post ejercicio. Finalmente, se combinan todos los aspectos mencionados: ingesta nutricional, RPE percepción del esfuerzo y fatiga, con el fin de conocer la situación actual del estudio de la relación entre dichas variables, conformando la base del segundo objetivo de este estudio. Seguidamente, se exponen y fundamentan los objetivos antes mencionados, para dar lugar después a la explicación de la metodología utilizada en el presente estudio. Ésta consistió en un diseño de estudios de caso, aplicándose una intervención nutricional personalizada a tres jugadores de baloncesto profesional (cada jugador = un estudio de caso; n = 1), con el objetivo de adecuar su ingesta nutricional en el largo plazo a las recomendaciones nutricionales. A su vez, se analizó la respuesta individual de cada uno de los casos a dicha intervención para los dos objetivos del estudio. Para ello, cada jugador completó un registro diario de alimentos (7 días; pesada de alimentos) antes, durante y al final de la intervención. Además, los sujetos registraron diariamente a lo largo del estudio la RPE-Sesión y la fatiga en entrenamientos físicos y de balón y en partidos oficiales de liga, controlándose además en forma cuantitativa otras variables influyentes como el estado de ánimo y el sueño. El análisis de los datos consistió en el cálculo de los estadísticos descriptivos para todas las variables, la comparación de la ingesta en los diferentes momentos evaluados con las recomendaciones nutricionales y una comparación de medias no paramétrica entre el período pre intervención y durante la intervención con el test de Wilcoxon (medidas repetidas) para todas las variables. Finalmente, se relacionaron los cambios obtenidos en la ingesta nutricional con la percepción del esfuerzo y la fatiga y la posible influencia del estado de ánimo y el sueño, a través de un estudio correlacional (Tau_b de Kendall). Posteriormente, se presentan los resultados obtenidos y la discusión de los mismos, haciendo referencia a la evidencia científica relacionada que se encuentra publicada hasta el momento, la cual facilitó el análisis de la relación entre RPE-Sesión, fatiga y nutrición a lo largo de una temporada. Los principales hallazgos y su correspondiente análisis, por lo tanto, pueden resumirse en los siguientes: 1) los tres jugadores de baloncesto profesional presentaron inicialmente hábitos nutricionales inadecuados, haciendo evidente la necesidad de un nutricionista deportivo dentro del cuerpo técnico de los equipos profesionales; 2) las principales deficiencias correspondieron a un déficit pronunciado de energía e hidratos de carbono, que fueron reducidas con la intervención nutricional; 3) la ingesta excesiva de grasa total, ácidos grasos saturados, etanol y proteínas que se halló en alguno/s de los casos, también se adecuó a las recomendaciones después de la intervención; 4) la media obtenida durante un período de la temporada para la RPE-Sesión y la fatiga de entrenamientos, podría ser disminuida en un jugador individual mediante el incremento de su ingesta de carbohidratos a largo plazo, siempre que no existan alteraciones psico-emocionales relevantes; 5) el comportamiento de la RPE-Sesión de partidos oficiales no parece estar influido por los factores nutricionales modificados en este estudio, dependiendo más de la variación de elementos externos no controlables, intrínsecos a los partidos de baloncesto profesional. Ante estos resultados, se pudo observar que las diferentes características de los jugadores y las distintas respuestas obtenidas después de la intervención, reforzaron la importancia de utilizar un diseño de estudio de casos para el análisis de los deportistas de élite y, asimismo, de realizar un asesoramiento nutricional personalizado. Del mismo modo, la percepción del esfuerzo y la fatiga de cada jugador evolucionaron de manera diferente después de la intervención nutricional, lo cual podría depender de las diferentes características de los sujetos, a nivel físico, psico-social, emocional y contextual. Por ello, se propone que el control riguroso de las variables cualitativas que parecen influir sobre la RPE y la fatiga a largo plazo, facilitaría la comprensión de los datos y la determinación de factores desconocidos que influyen sobre estas variables. Finalmente, al ser la RPE-Sesión un indicador directo de la carga interna del entrenamiento, es decir, del estrés psico-fisiológico experimentado por el deportista, la posible atenuación de esta variable mediante la adecuación de los hábitos nutricionales, permitiría aplicar las cargas externas de entrenamiento planificadas, con menor estrés interno y mejor recuperación entre sesiones, disminuyendo también la sensación de fatiga, a pesar del avance de la temporada. ABSTRACT This study consisted in a long-term nutritional intervention carried out with professional basketball players according to nutritional recommendations, with the following two main objectives: 1) to evaluate the changes produced by the intervention on daily nutritional practices of these athletes and 2) to determine the influence of long term nutritional intake modifications on the rate of perceived exertion per session (Session-RPE) and fatigue, throughout a competitive season for training as well as competition games. These objectives are based on: 1) much scientific evidence that shows an inadequacy of the nutritional habits of basketball players and other athletes regarding nutritional recommendations; 2) the fact widely recognized in the scientific literature that an optimal nutrition allows to achieve the maximum performance of an athlete (both physically and cognitively), promoting fast recovery and decreasing risks of sports injuries and illnesses. However, only few studies carried out a long term nutritional intervention to improve nutritional practices of athletes and it could not be found any research with basketball players; 3) the high correlation between the rate of perceived exertion (RPE) and physiological variables related to the performance of physical exercise (e.g.: heart rate, maximum consumption of oxygen or blood lactate) and multiple studies showing the attenuation of RPE during exercise due to the intake of certain nutrients (especially carbohydrates), while none of them was developed in basketball; 4) correlation between nutritional intake and Session-RPE has been recently studied for the first time. Session-RPE method has been validated in basketball players and other team sports as an indicator of internal workload, sports performance and exercise intensity; 5) fatigue is considered one of the main influential factor on RPE and sport performance. It has also been observed that carbohydrates intake may delay or mitigate the onset of fatigue and, thus, decrease the perceived exertion and the internal training load, which could improve sports performance and training-induced adaptations; 6) there are few studies evaluating the influence of nutrient intake on Session-RPE and only one of them has been carried out with basketball players. Moreover, it has not been analyzed the possible effects of the adequacy of players’ nutritional habits through a nutritional intervention on Session-RPE and fatigue, variables that could be decreased for all training session and competition games because of an improvement of daily nutritional intake. Therefore, this work begins with an introduction that provides the conceptual framework of this research focused on the key role of nutrition in sport, as well as on the current nutritional recommendations for athletes and specifically for basketball players. In addition, previous nutritional interventions carried out with other athletes are described, as well as consequential modifications on their food pattern, coinciding with the first objective of the present study. Subsequently, RPE, Session-RPE and fatigue are analyzed, with focus on their correlation with physical workload, training intensity, sports performance and recovery. Finally, all the aforementioned aspects (nutritional intake, RPE and fatigue) were combined in order to know the current status of the relation between each other, this being the base for the second objective of this study. Subsequently, the objectives mentioned above are explained, continuing with the explanation of the methodology used in the study. The methodology consisted of a case-study design, carrying out a long term nutritional intervention with three professional basketball players (each player = one case study; n = 1), in order to adapt their nutritional intake to nutritional recommendations. At the same time, the individual response of each player to the intervention was analyzed for the two main objectives of the study. Each player completed a food diary (7 days; weighing food) in three moments: before, during and at the end of the intervention. In addition, the Session-RPE and fatigue were daily recorded throughout the study for all trainings (training with ball and resistance training) and competition games. At the same time, other potentially influential variables such as mood state and sleeping were daily controlled throughout the study. Data analysis consisted in descriptive statistics calculation for all the variables of the study, the comparison between nutritional intake (evaluated at different times) and nutritional recommendations and a non-parametric mean comparison between pre intervention and during intervention periods was made by Wilcoxon test (repeated measurements) for all variables too. Finally, the changes in nutritional intake, mood state and sleeping were correlated with the perceived exertion and fatigue through correctional study (Tau_b de Kendall). After the methodology, the study results and the associated discussion are presented. The discussion is based on the current scientific evidence that contributes to understand the relation between Session-RPE, fatigue and nutrition throughout the competitive season. The main findings and results analysis can be summarized as follows: 1) the three professional basketball players initially had inadequate nutritional habits and this clearly shows the need of a sports nutritionist in the coaching staff of professional teams; (2) the major deficiencies of the three players’ diet corresponded to a pronounced deficit of energy intake and carbohydrates consumption which were reduced with nutritional intervention; (3) the excessive intake of total fat, saturated fatty acids, ethanol and protein found in some cases were also adapted to the recommendations after the intervention; (4) Session-RPE mean and fatigue of a certain period of the competition season, could be decreased in an individual player by increasing his carbohydrates intake in the long term, if there are no relevant psycho-emotional disorders; (5) the behavior of the Session-RPE in competition games does not seem to be influenced by the nutritional factors modified in this study. They seem to depend much more on the variation of external non-controllable factors associated with the professional basketball games. Given these results, the different characteristics of each player and the diverse responses observed after the intervention in each individual for all the variables, reinforced the importance of the use of a case study design for research with elite athletes as well as personalized nutritional counselling. In the same way, the different responses obtained for RPE and fatigue in the long term for each player due to modification of nutritional habits, show that there is a dependence of such variables on the physical, psychosocial, emotional and contextual characteristics of each player. Therefore it is proposed that the rigorous control of the qualitative variables that seem to influence the RPE and fatigue in the long term, may facilitate the understanding of data and the determination of unknown factors that could influence these variables. Finally, because Session-RPE is a direct indicator of the internal load of training (psycho-physiological stress experienced by the athlete), the possible attenuation of Session-RPE through the improvement in nutritional habits, would allow to apply the planned external loads of training with less internal stress and better recovery between sessions, with a decrease in fatigue, despite of the advance of the season.

INTERVENÇÕES FISIOTERAPÊUTICAS NUM CONTEXTO LÚDICO JUNTO A CRIANÇAS COM DOENÇAS RESPIRATÓRIAS CRÔNICAS

Verifica-se hoje em dia o aumento da incidência de problemas pulmonares que ocasiona internações hospitalares infantis com maior freqüência. Este projeto baseia-se na visão biopsicossocial da Psicologia da Saúde e leva em conta a valorização de atividades do cotidiano da criança, como o brincar, para sua recuperação. Tem por objetivo principal investigar se a utilização de técnicas interventivas lúdicas em fisioterapia contribui para a melhora dos níveis de oxigenação de crianças asmáticas e por objetivos específicos traçar um breve perfil clínico da criança que procura o Ambulatório de Alergia e Imunologia da Faculdade de Medicina do ABC e verificar a adesão da criança com problemas respiratórios a uma intervenção fisioterapêutica lúdica da criança. A análise qualitativa da intervenção lúdica registra grande envolvimento e participação prazerosa das crianças e ampla aceitação dos pais. Estes resultados sugerem que novas pesquisas sejam realizadas a respeito de intervenções lúdicas em fisioterapia. Utiliza-se de método avaliativo-interventivo quase-experimental. Seus participantes são 58 crianças de ambos os sexos com idade de quatro a 11 anos com as patologias de asma brônquica, bronquite e rinite alérgica, sem a presença da crise. Desenvolve-se por meio de sessão única com cada paciente, com avaliação antes e após da intervenção fisioterápica lúdica por meio das aferições dos sinais vitais, (PA, FC, FR,T°C, incluindo oximetria de pulso e PFE) técnicas de aquecimento, alongamento torácico, fortalecimento abdominal e expansão torácica. Realiza análise qualitativa da responsividade das crianças às técnicas interventivas empregadas no contexto lúdico. Os resultados a respeito do perfil clinico indicam maior incidência de Asma, com 44 casos (75,8620 %), para 11 casos de Rinite (18,9655 %) e apenas três de Bronquite (5,1724 %). Os dados relativos a PA, FC, FR,T°C e ao PFE mostram-se dentro da normalidade. Este estudo não constata diferença significativa em relação ao nível de saturação de O2 após a intervenção lúdica. Quanto à adesão, 55,2 % dos participantes aderiram, sendo que a não adesão deu-se por motivos particulares alegados pelos responsáveis ou indisposição da criança, de dor de cabeça, sonolência e/ou vômito. A análise qualitativa da intervenção lúdica registra grande envolvimento e participação prazerosa das crianças e ampla aceitação dos pais. Estes resultados sugerem que novas pesquisas sejam realizadas a respeito de intervenções lúdicas em fisioterapia.(AU)

INTERVENÇÕES FISIOTERAPÊUTICAS NUM CONTEXTO LÚDICO JUNTO A CRIANÇAS COM DOENÇAS RESPIRATÓRIAS CRÔNICAS

Verifica-se hoje em dia o aumento da incidência de problemas pulmonares que ocasiona internações hospitalares infantis com maior freqüência. Este projeto baseia-se na visão biopsicossocial da Psicologia da Saúde e leva em conta a valorização de atividades do cotidiano da criança, como o brincar, para sua recuperação. Tem por objetivo principal investigar se a utilização de técnicas interventivas lúdicas em fisioterapia contribui para a melhora dos níveis de oxigenação de crianças asmáticas e por objetivos específicos traçar um breve perfil clínico da criança que procura o Ambulatório de Alergia e Imunologia da Faculdade de Medicina do ABC e verificar a adesão da criança com problemas respiratórios a uma intervenção fisioterapêutica lúdica da criança. A análise qualitativa da intervenção lúdica registra grande envolvimento e participação prazerosa das crianças e ampla aceitação dos pais. Estes resultados sugerem que novas pesquisas sejam realizadas a respeito de intervenções lúdicas em fisioterapia. Utiliza-se de método avaliativo-interventivo quase-experimental. Seus participantes são 58 crianças de ambos os sexos com idade de quatro a 11 anos com as patologias de asma brônquica, bronquite e rinite alérgica, sem a presença da crise. Desenvolve-se por meio de sessão única com cada paciente, com avaliação antes e após da intervenção fisioterápica lúdica por meio das aferições dos sinais vitais, (PA, FC, FR,T°C, incluindo oximetria de pulso e PFE) técnicas de aquecimento, alongamento torácico, fortalecimento abdominal e expansão torácica. Realiza análise qualitativa da responsividade das crianças às técnicas interventivas empregadas no contexto lúdico. Os resultados a respeito do perfil clinico indicam maior incidência de Asma, com 44 casos (75,8620 %), para 11 casos de Rinite (18,9655 %) e apenas três de Bronquite (5,1724 %). Os dados relativos a PA, FC, FR,T°C e ao PFE mostram-se dentro da normalidade. Este estudo não constata diferença significativa em relação ao nível de saturação de O2 após a intervenção lúdica. Quanto à adesão, 55,2 % dos participantes aderiram, sendo que a não adesão deu-se por motivos particulares alegados pelos responsáveis ou indisposição da criança, de dor de cabeça, sonolência e/ou vômito. A análise qualitativa da intervenção lúdica registra grande envolvimento e participação prazerosa das crianças e ampla aceitação dos pais. Estes resultados sugerem que novas pesquisas sejam realizadas a respeito de intervenções lúdicas em fisioterapia.(AU)

Oxytocin releases atrial natriuretic peptide by combining with oxytocin receptors in the heart

Previous studies indicated that the central nervous system induces release of the cardiac hormone atrial natriuretic peptide (ANP) by release of oxytocin from the neurohypophysis. The presence of specific transcripts for the oxytocin receptor was demonstrated in all chambers of the heart by amplification of cDNA by the PCR using specific oligonucleotide primers. Oxytocin receptor mRNA content in the heart is 10 times lower than in the uterus of female rats. Oxytocin receptor transcripts were demonstrated by in situ hybridization in atrial and ventricular sections and confirmed by competitive binding assay using frozen heart sections. Perfusion of female rat hearts for 25 min with Krebs–Henseleit buffer resulted in nearly constant release of ANP. Addition of oxytocin (10−6 M) significantly stimulated ANP release, and an oxytocin receptor antagonist (10−7 and 10−6 M) caused dose-related inhibition of oxytocin-induced ANP release and in the last few minutes of perfusion decreased ANP release below that in control hearts, suggesting that intracardiac oxytocin stimulates ANP release. In contrast, brain natriuretic peptide release was unaltered by oxytocin. During perfusion, heart rate decreased gradually and it was further decreased significantly by oxytocin (10−6 M). This decrease was totally reversed by the oxytocin antagonist (10−6 M) indicating that oxytocin released ANP that directly slowed the heart, probably by release of cyclic GMP. The results indicate that oxytocin receptors mediate the action of oxytocin to release ANP, which slows the heart and reduces its force of contraction to produce a rapid reduction in circulating blood volume.

31P magnetic resonance spectroscopy of the Sherpa heart: a phosphocreatine/adenosine triphosphate signature of metabolic defense against hypobaric hypoxia.

Of all humans thus far studied, Sherpas are considered by many high-altitude biomedical scientists as most exquisitely adapted for life under continuous hypobaric hypoxia. However, little is known about how the heart is protected in hypoxia. Hypoxia defense mechanisms in the Sherpa heart were explored by in vivo, noninvasive 31P magnetic resonance spectroscopy. Six Sherpas were examined under two experimental conditions [normoxic (21% FiO2) and hypoxic (11% FiO2) and in two adaptational states--the acclimated state (on arrival at low-altitude study sites) and the deacclimating state (4 weeks of ongoing exposure to low altitude). Four lowland subjects were used for comparison. We found that the concentration ratios of phosphocreatine (PCr)/adenosine triphosphate (ATP) were maintained at steady-state normoxic values (0.96, SEM = 0.22) that were about half those found in normoxic lowlanders (1.76, SEM = 0.03) monitored the same way at the same time. These differences in heart energetic status between Sherpas and lowlanders compared under normoxic conditions remained highly significant (P < 0.02) even after 4 weeks of deacclimation at low altitudes. In Sherpas under acute hypoxia, the heart rate increased by 20 beats per min from resting values of about 70 beats per min, and the percent saturation of hemoglobin decreased to about 75%. However, these perturbations did not alter the PCr/ATP concentration ratios, which remained at about 50% of the values expected in healthy lowlanders. Because the creatine phosphokinase reaction functions close to equilibrium, these steady-state PCr/ATP ratios presumably coincided with about 3-fold higher free adenosine diphosphate (ADP) concentrations. Higher ADP concentrations (i.e., lower [PCr]/[ATP] ratios) were interpreted to correlate with the Km values for ADP-requiring kinases of glycolysis and to reflect elevated carbohydrate contributions to heart energy needs. This metabolic organization is postulated as advantageous in hypobaria because the ATP yield per O2 molecule is 25-60% higher with glucose than with free fatty acids (the usual fuels utilized in the human heart in postfasting conditions).

Hypertension in Pagothenia borchgrevinki caused by X-cell disease

Approximately 15% of a population of the cryopelagic nototheniid fish Pagothenia borchgrevinki, found constantly swimming immediately beneath the annual fast ice, in McMudro Sound. Ross Sea, Antarctica, was affected by X-cell gill disease. This disease affected blood flow through the gill lamellae, and this in turn affected oxygen uptake. Exercise caused increases in heart rate and ventral aortic blood pressure. Heart rate increased from 15.1 +/- 1.55 to 23.1 +/- 0.93 beats min(-1) in healthy fish, with a similar increase from 15.1 +/- 1.55 to 23.1 +/- 0.93 beats min(-1) in healthy fish, with a similar increase (to 24.6 +/- 0.26 beats min(-1)) in X-cell-affected animals. In healthy fish, pressures rose with exercise (from 2.72 +/- 0.11 to 3.75 +/- 0.19 kPa) and then rapidly returned to resting levels during recovery. In X-cell fish pressures rose during exercise, but then continued to rise, to reach a high of 4.18 +/- 0.13 kPa, close to the predicted maximum pressure able to be generated by these hearts. Recovery was rapid in healthy fish, but was prolonged in diseased animals. As they are constantly swimming, there is the potential that X-cell-affected fish suffer from chronic hypertension. (C) 2003 The Fisheries Society of the British Isles.

Response of B-type natriuretic pepticle to exercise in hypertensive patients with suspected diastolic heart failure: Correlation with cardiac function, hemodynamics, and workload

Background Diastolic heart failure (DHF) is characterized by dyspnea due to increased left ventricular (LV) filling pressures during stress. We sought the relationship of exercise-induced increases in B-type natriuretic peptide (BNP) to LV filling pressures and parameters of cardiovascular performance in suspected DHF. Methods Twenty-six treated hypertensive patients with suspected DHF (exertional dyspnea, LV ejection fraction >50%, and diastolic dysfunction) underwent maximal exercise echocardiography using the Bruce protocol. BNP, transmitral Doppler, and tissue Doppler for systolic (So) and early (Ea) and late (Aa) diastolic mitral annular velocities were obtained at rest and peak stress. LV filling pressures were estimated with E/Ea ratios. Results Resting BNP correlated with resting pulse pressure (r=0.45, P=0.02). Maximal exercise performance (4.6 +/- 2.5min) was limited by dyspnea. Blood pressure increased with exercise (from 143 +/- 19/88 +/- 8 to 191 +/- 22/90 +/- 10 mm Hg); 13 patients (50%) had a hypertensive response. Peak exercise BNP correlated with peak transmitral E velocity (r = 0.41, P <.05) and peak heart rate (r = -0.40, P <.05). BNP increased with exercise (from 48 57 to 74 97 pg/mL, P =.007), and the increment of BNP with exercise was associated with maximal workload and peak exercise So, Ea, and Aa (P <.01 for all). Filling pressures, approximated by lateral E/Ea ratio, increased with exercise (7.7 +/- 2.0 to 10.0 +/- 4.8, P <.01). BNP was higher in patients with possibly elevated filling pressures at peak exercise (E/Ea >10) compared to those with normal pressures (123 +/- 124 vs 45 +/- 71 pg/mL, P =.027). Conclusions Augmentation of BNP with exercise in hypertensive patients with suspected DHF is associated with better exercise capacity, LV systolic and diastolic function, and left atrial function. Peak exercise BNP levels may identify exercise-induced elevation of filling pressures in DHF.

The influence of bovine colostrum supplementation on exercise performance in highly trained cyclists

Purpose: The aim of this experiment was to investigate the influence of low dose bovine colostrum supplementation on exercise performance in cyclists over a 10 week period that included 5 days of high intensity training (HIT). Methods: Over 7 days of preliminary testing, 29 highly trained male road cyclists completed a VO2max test (in which their ventilatory threshold was estimated), a time to fatigue test at 110% of ventilatory threshold, and a 40 km time trial (TT40). Cyclists were then assigned to either a supplement (n = 14, 10 g/day bovine colostrum protein concentrate (CPC)) or a placebo group (n = 15, 10 g/day whey protein) and resumed their normal training. Following 5 weeks of supplementation, the cyclists returned to the laboratory to complete a second series of performance testing (week 7). They then underwent five consecutive days of HIT (week 8) followed by a further series of performance tests (week 9). Results: The influence of bovine CPC on TT40 performance during normal training was unclear (week 7: 1+/-3.1%, week 9: 0.1+/-2.1%; mean+/-90% confidence limits). However, at the end of the HIT period, bovine CPC supplementation, compared to the placebo, elicited a 1.9+/-2.2% improvement from baseline in TT40 performance and a 2.3+/-6.0% increase in time trial intensity (% VO2max), and maintained TT40 heart rate (2.5+/-3.7%). In addition, bovine CPC supplementation prevented a decrease in ventilatory threshold following the HIT period (4.6+/-4.6%). Conclusion: Low dose bovine CPC supplementation elicited improvements in TT40 performance during an HIT period and maintained ventilatory threshold following five consecutive days of HIT.

Prediction of functional capacity in chronic heart failure patients using myocardial tissue Doppler

Background. Exercise therapy improves functional capacity in CHF, but selection and individualization of training would be helped by a simple non-invasive marker of peak VO2. Peak VO2 in these pts is difficult to predict without direct measurement, and LV ejection fraction is a poor predictor. Myocardial tissue velocities are less load-dependent, and may be predictive of the exercise response in CHF pts. We sought to use tissue velocity as a predictor of peak VO2 in CHF pts. Methods. Resting 2D-echocardiography and tissue Doppler imaging were performed in 182 CHF pts (159 male, age 62±10 years) before and after metabolic exercise testing. The majority of these patients (129, 71%) had an ischemic cardiomyopathy, with resting EF of 35±13% and a peak VO2 of 13.5±4.7 ml/kg/min. Results. Neither resting EF (r=0.15) nor peak EF (r=0.18, both p=NS) were correlated with peak VO2. However, peak VO2 correlated with peak systolic velocity in septal (Vss, r=0.31) and lateral walls (Vsl, r=0.26, both p=0.01). In a general linear model (r2 = 0.25), peak VO2 was calculated from the following equation: 9.6 + 0.68*Vss - 0.09*age + 0.06*maximum HR. This model proved to be a superior predictor of peak VO2 (r=0.51, p=0.01) than the standard prediction equations of Wasserman (r= -0.12, p=0.01). Conclusions. Resting tissue Doppler, age and maximum heart rate may be used to predict functional capacity in CHF patients. This may be of use in selecting and following the response to therapy, including for exercise training.

INTERVENÇÕES FISIOTERAPÊUTICAS NUM CONTEXTO LÚDICO JUNTO A CRIANÇAS COM DOENÇAS RESPIRATÓRIAS CRÔNICAS

Verifica-se hoje em dia o aumento da incidência de problemas pulmonares que ocasiona internações hospitalares infantis com maior freqüência. Este projeto baseia-se na visão biopsicossocial da Psicologia da Saúde e leva em conta a valorização de atividades do cotidiano da criança, como o brincar, para sua recuperação. Tem por objetivo principal investigar se a utilização de técnicas interventivas lúdicas em fisioterapia contribui para a melhora dos níveis de oxigenação de crianças asmáticas e por objetivos específicos traçar um breve perfil clínico da criança que procura o Ambulatório de Alergia e Imunologia da Faculdade de Medicina do ABC e verificar a adesão da criança com problemas respiratórios a uma intervenção fisioterapêutica lúdica da criança. A análise qualitativa da intervenção lúdica registra grande envolvimento e participação prazerosa das crianças e ampla aceitação dos pais. Estes resultados sugerem que novas pesquisas sejam realizadas a respeito de intervenções lúdicas em fisioterapia. Utiliza-se de método avaliativo-interventivo quase-experimental. Seus participantes são 58 crianças de ambos os sexos com idade de quatro a 11 anos com as patologias de asma brônquica, bronquite e rinite alérgica, sem a presença da crise. Desenvolve-se por meio de sessão única com cada paciente, com avaliação antes e após da intervenção fisioterápica lúdica por meio das aferições dos sinais vitais, (PA, FC, FR,T°C, incluindo oximetria de pulso e PFE) técnicas de aquecimento, alongamento torácico, fortalecimento abdominal e expansão torácica. Realiza análise qualitativa da responsividade das crianças às técnicas interventivas empregadas no contexto lúdico. Os resultados a respeito do perfil clinico indicam maior incidência de Asma, com 44 casos (75,8620 %), para 11 casos de Rinite (18,9655 %) e apenas três de Bronquite (5,1724 %). Os dados relativos a PA, FC, FR,T°C e ao PFE mostram-se dentro da normalidade. Este estudo não constata diferença significativa em relação ao nível de saturação de O2 após a intervenção lúdica. Quanto à adesão, 55,2 % dos participantes aderiram, sendo que a não adesão deu-se por motivos particulares alegados pelos responsáveis ou indisposição da criança, de dor de cabeça, sonolência e/ou vômito. A análise qualitativa da intervenção lúdica registra grande envolvimento e participação prazerosa das crianças e ampla aceitação dos pais. Estes resultados sugerem que novas pesquisas sejam realizadas a respeito de intervenções lúdicas em fisioterapia.(AU)

Constitutive glycogen synthase kinase-3α/β activity protects against chronic β-adrenergic remodelling of the heart

Aims - Glycogen synthase kinase 3 (GSK-3) signalling is implicated in the growth of the heart during development and in response to stress. However, its precise role remains unclear. We set out to characterize developmental growth and response to chronic isoproterenol (ISO) stress in knockin (KI) mice lacking the critical N-terminal serines, 21 of GSK-3 and 9 of GSK-3 respectively, required for inactivation by upstream kinases. Methods and results - Between 5 and 15 weeks, KI mice grew more rapidly, but normalized heart weight and contractile performance were similar to wild-type (WT) mice. Isolated hearts of both genotypes responded comparably to acute ISO infusion with increases in heart rate and contractility. In WT mice, chronic subcutaneous ISO infusion over 14 days resulted in cardiac hypertrophy, interstitial fibrosis, and impaired contractility, accompanied by foetal gene reactivation. These effects were all significantly attenuated in KI mice. Indeed, ISO-treated KI hearts demonstrated reversible physiological remodelling traits with increased stroke volume and a preserved contractile response to acute adrenergic stimulation. Furthermore, simultaneous pharmacological inhibition of GSK-3 in KI mice treated with chronic subcutaneous ISO recapitulated the adverse remodelling phenotype seen in WT hearts. Conclusion - Expression of inactivation-resistant GSK-3/does not affect eutrophic myocardial growth but protects against pathological hypertrophy induced by chronic adrenergic stimulation, maintaining cardiac function and attenuating interstitial fibrosis. Accordingly, strategies to prevent phosphorylation of Ser-21/9, and consequent inactivation of GSK-3/, may enable a sustained cardiac response to chronic-agonist stimulation while preventing pathological remodelling. © 2010 The Author.

PSD modifications of FHRV due to interpolation and CTG storage rate

Cardiotocographic data provide physicians information about foetal development and permit to assess conditions such as foetal distress. An incorrect evaluation of the foetal status can be of course very dangerous. To improve interpretation of cardiotocographic recordings, great interest has been dedicated to foetal heart rate variability spectral analysis. It is worth reminding, however, that foetal heart rate is intrinsically an uneven series, so in order to produce an evenly sampled series a zero-order, linear or cubic spline interpolation can be employed. This is not suitable for frequency analyses because interpolation introduces alterations in the foetal heart rate power spectrum. In particular, interpolation process can produce alterations of the power spectral density that, for example, affects the estimation of the sympatho-vagal balance (computed as low-frequency/high-frequency ratio), which represents an important clinical parameter. In order to estimate the frequency spectrum alterations of the foetal heart rate variability signal due to interpolation and cardiotocographic storage rates, in this work, we simulated uneven foetal heart rate series with set characteristics, their evenly spaced versions (with different orders of interpolation and storage rates) and computed the sympatho-vagal balance values by power spectral density. For power spectral density estimation, we chose the Lomb method, as suggested by other authors to study the uneven heart rate series in adults. Summarising, the obtained results show that the evaluation of SVB values on the evenly spaced FHR series provides its overestimation due to the interpolation process and to the storage rate. However, cubic spline interpolation produces more robust and accurate results. © 2010 Elsevier Ltd. All rights reserved.

Effects of hydrogen sulphide on the isolated perfused rat heart

Objectives: Hydrogen sulphide has been identified as a gas signalling molecule in the body, and has previously been shown to have vasorelaxant properties. The aim of the study was to investigate the effects of sodium hydrosulphide (NaHS), a hydrogen sulphide donor, on heart rate (HR), left ventricular developed pressure (LVDP) and coronary flow (CF) in the isolated perfused rat heart. Methods: A Langendorff isolated heart preparation was used to investigate the effect of a dose range of sodium hydrosulphide, in the presence and absence of inhibitors, on heart rate, left ventricular developed pressure and coronary flow. Results: Sodium hydrosulphide caused a significant decrease in heart rate at a concentration of 10-3 M (P <0.001). This decrease was partially inhibited by glibenclamide, a K ATP channel blocker (P <0.05); L-NAME, a nitric oxide synthase inhibitor (P <0.001), and methylene blue (P <0.001), but not by H-89, a protein kinase A inhibitor. Sodium hydrosulphide significantly increased coronary flow at concentrations of 10-4 - 10-3M (P <0.05). This response was significantly increased in the presence of L-NAME (P <0.001) and methylene blue (P <0.001), whereas H-89 inhibited the increase in coronary flow due to sodium hydrosulphide (P <0.001). Sodium hydrosulphide significantly decreased LVDP at all concentrations (P <0.001). In the presence of glibenclamide and H-89, the time period of the decrease in LVDP due to sodium hydrosulphide was extended (P <0.001), whereas methylene blue and L-NAME caused a significant reduction in the response to sodium hydrosulphide (P <0.05, P <0.01 respectively). Conclusion: Sodium hydrosulphide reduced heart rate and LVDP, and increased coronary flow in the isolated perfused rat heart; however, the mechanisms of action could not be fully elucidated.

Preservation of myocardial beta-adrenergic receptor signaling delays the development of heart failure after myocardial infarction.

When the heart fails, there is often a constellation of biochemical alterations of the beta-adrenergic receptor (betaAR) signaling system, leading to the loss of cardiac inotropic reserve. betaAR down-regulation and functional uncoupling are mediated through enhanced activity of the betaAR kinase (betaARK1), the expression of which is increased in ischemic and failing myocardium. These changes are widely viewed as representing an adaptive mechanism, which protects the heart against chronic activation. In this study, we demonstrate, using in vivo intracoronary adenoviral-mediated gene delivery of a peptide inhibitor of betaARK1 (betaARKct), that the desensitization and down-regulation of betaARs seen in the failing heart may actually be maladaptive. In a rabbit model of heart failure induced by myocardial infarction, which recapitulates the biochemical betaAR abnormalities seen in human heart failure, delivery of the betaARKct transgene at the time of myocardial infarction prevents the rise in betaARK1 activity and expression and thereby maintains betaAR density and signaling at normal levels. Rather than leading to deleterious effects, cardiac function is improved, and the development of heart failure is delayed. These results appear to challenge the notion that dampening of betaAR signaling in the failing heart is protective, and they may lead to novel therapeutic strategies to treat heart disease via inhibition of betaARK1 and preservation of myocardial betaAR function.

Seawater carbonate chemistry and growth rate during experiments with coral Acropora cervicornis, 2005

The growth rate of Acropora cervicornis branch tips maintained in the laboratory was measured before, during, and after exposure to elevated nitrate (5 and 10 µM NO3-), phosphate (2 and 4 µM P-PO43) and/or pCO2 (CO2 ~700 to 800 µatm). The effect of increased pCO2 was greater than that of nutrient enrichment alone. High concentrations of nitrate or phosphate resulted in significant decreases in growth rate, in both the presence and absence of increased pCO2. The effect of nitrate and phosphate enrichment combined was additive or antagonistic relative to nutrient concentration and pCO2 level. Growth rate recovery was greater after exposure to increased nutrients or CO2 compared to increased nutrients and CO2. If these results accurately predict coral response in the natural environment, it is reasonable to speculate that the survival and reef-building potential of this species will be significantly negatively impacted by continued coastal nutrification and projected pCO2 increases.