Physiological cardiovascular functions show daily diurnal variations, which are synchronized by intrinsic molecular clocks and environment-driven cues. The clinical manifestation of cardiovascular disease also exhibits diurnal variation, with an increased incidence in the early morning. This coincides with circadian oscillations of circulating parameters, such as hormones and leukocyte counts. ...

Serotonin is known to modulate the response of neuronal populations in the primary olfactory center of the moth olfactory system, the antennal lobe. Here, we analyzed the effects of serotonin on the behavior related to the restricted pheromone olfactory pathway of the male silkmoth, Bombyx mori. In order to understand the effects of serotonin at the behavioral level, we applied serotonin (10(-5...

The aim of the present study was to evaluate diurnal variations of the variability and irregularity of heart rate (HR) in patients with permanent atrial fibrillation (AF) with and without rate control drugs. Thirty-eight patients with permanent AF were part of an investigator-blind crossover study comparing diltiazem, verapamil, metoprolol, and carvedilol. We analyzed five Holter recordings per...

The activity of dihydropyrimidine dehydrogenase (DPD) in peripheral blood mononudear cells and plasma concentration of 5-fluorouracil (FUra) were simultaneously determined in cancer patients receiving FUra by protracted continuous infusion (300 mg/m!/day). Blood samples were drawn every 3 h over 24-h period and the resulting DPD and FUra values analyzed for circadian periodicity. In the seven p...

Many temperate insects take advantage of longer growing seasons at lower latitudes by increasing their generation number or voltinism. In some insects, development time abruptly decreases when additional generations are fit into the season. Consequently, latitudinal 'sawtooth' clines associated with shifts in voltinism are seen for phenotypes correlated with development time, like body size. Ho...

The mammalian circadian clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus and in most peripheral tissues. Clock genes drive the biological clock. However, circadian expression variations of the human clock genes are still unclear. In this study, we analyzed the daily variations of mPer2 and mClock mRNA expression in both the mouse SCN and liver to evaluate the central an...

OBJECTIVES/HYPOTHESIS Two undesired effects of the aminoglycoside antibiotic gentamicin are ototoxicity and nephrotoxicity. This study investigated if these adverse effects vary according to the circadian time of its administration. STUDY DESIGN This study entails laboratory animal research. METHODS Four groups of Sprague-Dawley rats were synchronized to a 12:12 light/dark schedule. Each gr...

BACKGROUND AND PURPOSE While previous studies suggest that the peak time period for the occurrence of ischemic stroke is in the mid- to late-morning hours, detailed information pertaining to circadian variations among the various stroke subtypes has been limited. The purpose of our study was to define the circadian patterns of symptom onset in an acute stroke trial with an established system fo...

The activity of dihydropyrimidine dehydrogenase (DPD) in peripheral blood mononudear cells and plasma concentration of 5-fluorouracil (FUra) were simultaneously determined in cancer patients receiving FUra by protracted continuous infusion (300 mg/m!/day). Blood samples were drawn every 3 h over 24-h period and the resulting DPD and FUra values analyzed for circadian periodicity. In the seven p...

The circadian system may regulate adult neurogenesis via intracellular molecular clock mechanisms or by modifying the environment of neurogenic niches, with daily variation in growth factors or nutrients depending on the animal's diurnal or nocturnal lifestyle. In a diurnal vertebrate, zebrafish, we studied circadian distribution of immunohistochemical markers of the cell division cycle (CDC) i...