RESUMEN
OBJECTIVE: To evaluate the contribution of the calf veins distension during stand test to orthostatic intolerance (OI). METHOD: The population consisted of a control group (Co, n=9) and an exercise (Fly-Wheel) counter-measure group (CM, n=9). Calf vein cross section area was assessed by echography during pre and post HDT stand-tests. RESULTS: Tibial, and muscular vein section at rest did not change during HDT in both groups. From supine to standing, the Tibial and muscular vein section increased significantly more at post HDT in non tolerant subjects, compare to pre HDT (tibial V: +122% from pre-HDT, muscular V: +145% p<005). In tolerant subjects the vein cross section increase from supine to stand was similar pre and post HDT. CONCLUSION: Fly-Wheel CM, did not reduce OI. High calf vein section increase at post-HDT stand-test compare to pre-HDT was significantly correlated with OI but not with CM.
Asunto(s)
Ejercicio Físico/fisiología , Hipotensión Ortostática/fisiopatología , Pierna/irrigación sanguínea , Pierna/diagnóstico por imagen , Postura/fisiología , Medidas contra la Ingravidez , Adulto , Reposo en Cama , Inclinación de Cabeza , Humanos , Hipotensión Ortostática/diagnóstico por imagen , Masculino , Posición Supina , Pruebas de Mesa Inclinada , Ultrasonografía , Venas/fisiologíaRESUMEN
Determination of whether the major metabolite of nandrolone in urine, 19-norandrosterone (19-NA), is exogenous or endogenous in origin is one of the most exciting challenges for antidoping laboratories. Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) can be used to differentiate these two origins by carbon isotopic ratio analysis. A complete method for purification of 19-NA in urine has been established. Acetylated ketosteroids, and in particular 19-NA, are isolated from the urine matrix before analysis after hydrolysis and purification of urine by reversed-phase and normal solid-phase extraction. The limit of detection for 19-NA was about 60 ng with recoveries of 54-60%. Evidence of exogenous administration of 19-NA may be established from isotope ratio determination from the 13C/12C ratios of several synthetic 19-norsteroids compared to those obtained for endogenous steroids.