RESUMO
Objective: The aim of this study was to determine the level of sleepiness/alertness among different chronotypes.Background: The Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) has allowed the characterization of chronotypes that are associated with a number of biological factors including: body temperature, cortisol rhythm, sleep patterns, and architecture.Methods: Fifty-six consecutive normal volunteers underwent an 8-h polysomnogram followed by a multiple sleep latency test (MSLT). Each subject also completed the MEQ and the Sleep/Wake Activity Inventory.Results: Evening types (ET) reported significantly later bedtimes and risetimes than both morning types (MT) and neither types (NT, P<0.05). On nocturnal polysomnography, the ET documented significantly longer latencies to stage 1 and persistent sleep when compared to both the NT and MT (P<0.01). There were no significant differences in the level of sleepiness on the MSLT across the different chronotypes. However, the pattern of sleepiness differed among them. While ET and NT showed differential sleep latencies across nap opportunities, MT showed no evidence of circadian variation on their level of sleepiness.Conclusions: There were no overall differences in daytime sleepiness/alertness across chronotypes. However, a differential pattern of sleep latencies was noted on the MSLT.
RESUMO
A method for the determination of okadaic acid, a typical DSP toxin, in mussels is described. The homogenized hepatopancreas is extracted and the crude extract purified by liquid/liquid partition chromatography. The derivatization of okadaic acid to 9-anthrylmethyl-okadaic acid (9-AM-OA) is achieved using the derivatization reagent 9-anthryldiazomethane (ADAM) and the clean-up is carried out by SPE with silica gel. 9-AM-OA is determined by HPLC using a RP-18 column with CH3CN/THF/H2O as the eluent. The selective and sensitive detection of 9-AM-OA is performed by coupling UV and fluorimetric detectors (detection limit: 0.5 microgram okadaic acid/g hepatopancreas).
