RESUMEN
BACKGROUND: Diffusion tensor imaging (DTI) studies have consistently shown white matter (WM) microstructural abnormalities in schizophrenia. Whether or not such alterations could vary depending on clinical status (i.e. acute psychosis v. remission) remains to be investigated. METHODS: Twenty-five treatment-naïve first-episode psychosis (FEP) patients and 51 healthy-controls (HC) underwent MRI scanning at baseline. Twenty-one patients were re-scanned as soon as they achieved sustained remission of symptoms; 36 HC were also scanned twice. Rate-of-change maps of longitudinal DTI changes were calculated for in order to examine WM alterations associated with changes in clinical status. We conducted voxelwise analyses of fractional anisotropy (FA) and trace (TR) maps. RESULTS: At baseline, FEP presented reductions of FA in comparison with HC [p < 0.05, false-discovery rate (FDR)-corrected] affecting fronto-limbic WM and associative, projective and commissural fasciculi. After symptom remission, patients showed FA increase over time (p < 0.001, uncorrected) in some of the above WM tracts, namely the right anterior thalamic radiation, right uncinate fasciculus/inferior fronto-occipital fasciculus, and left inferior fronto-occipital fasciculus/inferior longitudinal fasciculus. We also found significant correlations between reductions in PANSS scores and FA increases over time (p < 0.05, FDR-corrected). CONCLUSIONS: WM changes affecting brain tracts critical to the integration of perceptual information, cognition and emotions are detectable soon after the onset of FEP and may partially reverse in direct relation to the remission of acute psychotic symptoms. Our findings reinforce the view that WM abnormalities in brain tracts are a key neurobiological feature of acute psychotic disorders, and recovery from such WM pathology can lead to amelioration of symptoms.
Asunto(s)
Imagen de Difusión Tensora/métodos , Progresión de la Enfermedad , Trastornos Psicóticos/patología , Trastornos Psicóticos/fisiopatología , Sustancia Blanca/patología , Adolescente , Adulto , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Trastornos Psicóticos/diagnóstico por imagen , Trastornos Psicóticos/terapia , Inducción de Remisión , Sustancia Blanca/diagnóstico por imagen , Adulto JovenRESUMEN
AIM: The aim of this investigation was to study the physiological response to laboratory tests in elite and professional cyclists, and to relate it to the level at which riders compete and their specialization. METHODS: A total of 71 cyclists were divided into two groups, elite and professional, and were assessed for physical measurements, a maximal graded test and a 30 s all-out test, both performed on a cycle ergometer. The sample included 24 uphill riders (UR), 32 flat terrain riders (FTR), 11 all terrain riders (ATR) and 4 sprinters (SP). RESULTS: Professional riders showed significantly higher gross mechanical efficiency (GME) than their elite counterparts (25.6+/-2.6 vs 24.4+/-2%), but otherwise no other physiological differences emerged from the comparison between these two groups. However, many differences exist as a function of rider specialization, especially between UR and FTR. Compared with FTR, UR showed a higher VO2max (78.2+/-5.5 vs 72.6+/-6.5 mL x min(-1) x kg(-1)) and a lower maximal aerobic power (438.5+/-40.8 vs 465.3+/-36.2 W). From the 30 s all-out test, SP presents the highest maximal power (P < 0.05) and maximal velocity (P < 0.05) compared with all the other groups. CONCLUSIONS: The results for GME indicate a better efficiency for professional riders and suggest the importance of technical aspects related to movement pattern in cycling. The sensitivity of the maximal graded test and the 30 s all-out test did not allowed other differentiations between elite and professional cyclists.
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Ciclismo/fisiología , Conducta Competitiva , Adulto , Umbral Anaerobio/fisiología , Análisis de Varianza , Ciclismo/clasificación , Composición Corporal , Conducta Competitiva/fisiología , Ergometría , Tolerancia al Ejercicio , Humanos , Masculino , Sensibilidad y EspecificidadRESUMEN
AIM: The aim of this investigation is to evaluate the physical and physiological characteristics of different first (ProA) and second division (ProB) professional basketball players, and to relate them to playing position and level of play. METHODS: A total of 58 players were divided into ProA and ProB groups and were assessed for physical characteristics, maximal treadmill test and a 30 s all-out test. The sample included 22 centers, 22 forwards and 14 guards. RESULTS: Centers were significantly taller and heavier (203.9+/-5.3 cm and 103.9+/-12.4 kg) than forwards (195.8+/-4.8 cm and 89.4+/-7.1 kg) and guards (185.7+/-6.9 and 82+/-8.8 kg) and also had higher body fat percentages than the other groups. Forwards were also significantly taller than guards. Centers presented a lower maximal aerobic velocity (kmxh-1) than guards (15.5+/-1.2 vs 16.8+/-1.5, P<0.05) on the maximal treadmill test and a lower maximal velocity (rpm) than forwards (156.5+/-18.4 vs 170.3+/-18.3, P<0.05) on the 30 s all-out test. VO2max (mlxmin-1xkg-1) was significantly lower for ProA (53.7+/-6.7) compared to ProB (56.5+/-7.7) players and the fatigue index on the 30 s all-out test was higher for the ProA group (P<0.05). CONCLUSION: Many physical differences, most notably size, exist between players as a function of their playing position. But these differences have no relationship to the level of play of professional players. General aerobic capacity is fairly homogeneous between playing position and level of play, even if there are observable VO2max differences due to inter-individual profiles. On the other hand, anaerobic capacity seems to be a better predictor of playing level even though it is not clear whether such capacity comes from specific training in ProA, or from an initial selection criteria.
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Baloncesto/fisiología , Prueba de Esfuerzo , Ejercicio Físico/fisiología , Adulto , Umbral Anaerobio/fisiología , Antropometría , Fatiga/fisiopatología , Francia , Humanos , Masculino , Resistencia Física/fisiologíaRESUMEN
BACKGROUND: Breathe Right (BR) external nasal dilator have become increasingly popular over the past few years, however, the physiological basis for using BR remains unclear. We have examined whether alteration in nasal ventilation would influence the metabolic cost of submaximal running. METHODS: Metabolic cost was estimated in 10 male endurance triathletes by measuring heart rate (HR) and exercise perception by measuring the rate of perceived exertion (RPE) during submaximal field running. The protocol consisted of 5 min of running at 80% of their maximal aerobic velocity (MAV(f), previously determined under field conditions) for three randomised experimental conditions, separated by a 10 min rest. The conditions were normal nasal ventilation (N), no nasal ventilation (using a nose clip) (NC) and with a BR. RESULTS: Running with the BR or with NC did not significantly influence HR (N: 173+/-7, BR: 173+/-8, NC: 172+/-7 beat x min(-1); F=0.01, p=0.99) or RPE (N: 12.1+/-1.7, BR: 11.8+/-1.9, NC: 13.2+/-0.8; F=1.88, p=0.18). We conclude that alteration in nasal ventilation produced by using BR or NC do not influence HR or RPE in a group of triathletes running 5 min at 80% of MAV(f). CONCLUSIONS: The present study tended to demonstrate that both nasal ventilation would not influence the total metabolic cost, and that the BR device is not advantageous during high intensity exercise.