Sleep and Biological Rhythms via MedWorm.com

Factor structure of a Cantonese‐version Pittsburgh Sleep Quality Index

Sleep and Biological Rhythms — Thu, 19 Jan 2012 05:00:00 +0100

The objectives of this study were to translate, validate and test the factor structure of a Cantonese version of the Pittsburgh Sleep Quality Index (Cantonese‐PSQI) in support of its use among Cantonese‐speaking Chinese in Hong Kong, southern China and Chinese immigrant communities in the West.The study involved Cantonese‐speaking Chinese aged 45 or over in Hong Kong. A cross‐sectional survey of 97 participants was firstly conducted to validate the Cantonese‐PSQI. A second survey of 794 participants identified the best‐fitted factor structure of the scale. Confirmatory factor analysis then functioned to develop and test a single‐factor model, a two‐factor model, and a three‐factor model. The one‐factor model turned out to be unacceptable due to its poor fit (L2= 303.408...

Factors that predict adherence to continuous positive airway pressure treatment in obstructive sleep apnea patients: A prospective study in Japan

Sleep and Biological Rhythms — Sun, 01 Jan 2012 05:00:00 +0100

AbstractAs adherence to continuous positive airway pressure (CPAP) therapy is crucial in the successful management of obstructive sleep apnea (OSA), identification of the many factors that affect adherence is important. To identify these factors among OSA patients in Japan, a nation with a unique health insurance system, complete sets of data were collected from 101 patients who had undergone overnight diagnostic polysomnography and 6 months of therapy, and the data were subjected to univariate and multivariate analysis. The data included patient responses to sets of questionnaires containing items regarding a variety of factors that the patients had completed before undergoing overnight polysomnography for CPAP titration and initiating use of a treatment device. At the end of the treatm...

The Abstracts of Worldsleep2011

Sleep and Biological Rhythms — Sun, 01 Jan 2012 05:00:00 +0100

(Source: Sleep and Biological Rhythms)

Sleepiness during shift work in Japanese nurses: A comparison study using JESS, SSS, and actigraphy

Sleep and Biological Rhythms — Sun, 01 Jan 2012 05:00:00 +0100

AbstractThe present cross‐sectional survey of shift‐working nurses investigated the characteristics of the Japanese version of the Epworth Sleepiness Scale (JESS), the Stanford Sleepiness Scale (SSS) and actigraphy. Subjects comprised 51 nurses recruited from among participants of the Gunma Nurses' Health Study. The self‐check lists used were the JESS for “recent sleepiness” and the SSS for “current sleepiness.” Actigraphy was performed using an Actiwatch worn for 7–9 days. Subjects also kept a sleep diary. Prevalence of excessive daytime sleepiness was determined using a cut‐off value of 11 for total JESS score. SSS was administered at 2‐h intervals from the time of starting work until shift completion. Mean (±standard deviation) JESS score was 10.4 ± 3.6; scores w...

Effect of yokukansan on psychophysiological insomnia evaluated using cyclic alternating pattern as an objective marker of sleep instability

Sleep and Biological Rhythms — Thu, 22 Dec 2011 05:00:00 +0100

AbstractIn this open‐label study using final evaluator blinding, the efficacy of yokukansan (YKS) was evaluated in six psychophysiological insomnia patients using the cyclic alternating pattern (CAP) method. YKS had no influence on objective sleep parameters by the Rechtschaffen & Kales method, but the CAP rate and CAP cycle frequency decreased significantly. In the subjective Visual Analog Scale test, significant improvement was seen in five items: tension, calmness, fatigue, heavy‐headedness and lassitude. No adverse reactions were noted. YKS improved sleep quality without influencing sleep structure and showed no adverse reactions, suggesting that YKS is an effective anti‐insomnia drug with good tolerability. (Source: Sleep and Biological Rhythms)

Is circadian type associated with sleep duration in twins?

Sleep and Biological Rhythms — Sun, 04 Dec 2011 05:00:00 +0100

AbstractWe used the community‐based University of Washington Twin Registry to investigate the genetic association between circadian type and sleep duration. Habitual sleep duration was obtained by self‐report and circadian type was measured using a reduced 5‐item Horne–Östberg Morningness–Eveningness questionnaire. Univariate and bivariate genetic analyses were fit using structural equation models. We used multinomial logistic regression to examine the overall and within‐pair effects of circadian type on sleep duration in total and monozygotic (MZ) restricted twin samples. We surveyed 1620 twins, mostly female (70%), from same‐sex pairs (1098 monozygotic, 522 dizygotic) with a mean age of 36 years (SD = 15). Among all twins, 23% were habitual short (<7 h/night), 68%...

Sleep habits of Iranian pre‐school children in an urban area: Late sleeping and sleep debt in children

Sleep and Biological Rhythms — Mon, 10 Oct 2011 04:00:00 +0100

AbstractUsing BEARS (Bedtime problems, Excessive sleepiness, Awakenings during the night, Regularity of sleep, Snoring), and CSHQ (Children's Sleep Habits Questionnaires) screening tools with 224 participants revealed that Iranian children have shorter night sleep duration than expected (9.54 vs 12 h) for their age group. Earlier sleepers had longer night sleep duration (10:36 ± 1:12; 9:12 ± 1:06 h, P < 0.001), and total daily sleep time (11:36 ± 1:42; 10:36 ± 1:30 h, P= 0.005) than late sleepers. A majority (85%) of nap‐takers had sleep bedtime of 22:00 or later. The poor sleep quality of Iranian preschool children is probably due to cultural characteristics, climate differences, or harmful sleep habits. (Source: Sleep and Biological Rhythms)

Impact of lifestyle on circadian orientation and sleep behaviour

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

This study was conducted on 2105 subjects living in remote (500; without electricity), rural (500; with electricity) and urban areas (1105) having access to modern amenities of Chhattisgarh, India. Horne –Östberg questionnaires were used to find out the prevalence of morningness/eveningness. Sleep parameters and excessive daytime sleepiness were also evaluated with the help of questionnaires and the Epworth sleepiness scale. According to the Horne and Östberg classification, 83.87% of the total population was classified as morning type (MT), 13.30% as intermediate type (IT) and 3.23% people were reported as evening type (ET) with a significant difference (P < 0.001) in distribution of chronotype. The frequencies of MT people in remote, rural and urban areas were 99.60%, 95.20%, and ...

Are parents' working patterns associated with their child's sleep? An analysis of dual‐parent families in Australia

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

AbstractInsufficient sleep in children predicts emotional and behavioral problems, poorer school performance, and health problems. Child sleep durations have declined in recent decades, suggesting a need to identify and understand predictors of short sleep. The present study investigated whether aspects of parental employment (i.e. parental work hours, and non‐standard work hours) were associated with sleep in children. Data collected from 2477 children aged 6–7 years as part of the Longitudinal Study of Australian Children were used in this paper. Child sleep duration, bedtimes, and wake times were determined from parent self‐report using time‐use diaries. Parents completed a survey assessing their work patterns as well as a range of other demographic and social factors. The res...

Actigraphic sleep and developmental progress of one‐year‐old infants

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

AbstractThe aims of this study were to pilot methods to monitor the sleep of infants, as well as explore the relationships between infant sleep and physical, cognitive and motor development. Fifty‐two one‐year‐old infants and their parents participated in the study. Infant sleep was assessed by one week's actigraphy, sleep diaries and by the Brief Infant Sleep Questionnaire. Parents also completed a background questionnaire and the Ages and Stages Questionnaire to measure stages of development across five domains. Infant's weight and length were measured by the researcher at study onset and Body Mass Index (BMI) scores were calculated. Sleep efficiency, and having a higher proportion of total sleep at night, were significantly correlated with age as well as stages of cognitive and mo...

Effects of regularizing sleep–wake schedules on daytime autonomic functions and psychological states in healthy university students with irregular sleep–wake habits

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

AbstractThe present study examined the effects of regularizing sleep–wake schedules on sleep, autonomic function and mood/emotional and personality states in 14 habitually irregular sleepers. During the experiment, sleep monitoring and regularized sleep–wake schedules were conducted at home. First, the subjects' habitual sleep–wake patterns were strictly monitored for 6 days (Session 1); second, subjects' irregular sleep–wake patterns were regularized for 6 days (Session 2); and finally, subjects reverted from their regularized sleep–wake schedules to their original, habitual sleep–wake schedules and were monitored for 6 days (Session 3). Assessments in the laboratory, which were conducted in the daytime, were repeated four times. The first three assessments were carried ...

Sleep length, working hours and socio‐demographic variables are associated with time attending evening classes among working college students

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

AbstractIt is the aim of the present study to assess factors associated with time spent in class among working college students. Eighty‐two working students from 21 to 26 years old participated in this study. They were enrolled in an evening course of the University of São Paulo, Brazil. Participants answered a questionnaire on living and working conditions. During seven consecutive days, they wore an actigraph, filled out daily activity diaries (including time spent in classes) and the Karolinska Sleepiness Scale every three hours from waking until bedtime. Linear regression analyses were performed in order to assess the variables associated with time spent in classes. The results showed that gender, sleep length, excessive sleepiness, alcoholic beverage consumption (during workdays)...

Poster presentations 2

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Poster presentations 1

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Abstract symposia

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Industrial symposia

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

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Educational symposia

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

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Educational lectures

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Plenary symposia

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Plenary lectures

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Opening lecture

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Presidential lectures

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Welcome to Kyoto, Worldsleep2011/JSSR

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Promotion of non–rapid eye movement sleep in mice after oral administration of ornithine

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

We examined the effects of ornithine on the sleep–wake cycle by monitoring the electroencephalogram, electromyogram, and locomotor activity of freely moving mice after oral administration of it at lights‐off time (18:00). Ornithine (1.0 and 3.0 g/kg of body weight) increased the amount of non–rapid eye movement (non‐REM, NREM) sleep for 2 h after its administration, with a peak at 60 min post administration, to 164% and 198%, respectively, of that of the vehicle‐administered mice, without changing the amount of REM sleep. The administration of ornithine at a lower dose (0.3 g/kg of body weight) did not increase the amount of NREM sleep compared with the vehicle administration. Ornithine did not affect the power spectrum density of NREM sleep but increased the number of ep...

Factors differentiating infants identified by parents as problem sleepers, and those that are not

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

This study highlights factors contributing to parental perception of problem sleep which is vital for recognizing and managing such problems throughout infancy. (Source: Sleep and Biological Rhythms)

Author Index

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Poster Presentations

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Plenary Sessions

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Preface

Sleep and Biological Rhythms — Sat, 01 Oct 2011 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Ecstasy and sleep disturbance: Progress towards elucidating a role for the circadian system

Sleep and Biological Rhythms — Wed, 24 Aug 2011 23:00:00 +0100

AbstractMDMA (ecstasy) is an illicit drug which has pharmacological actions on the serotonin system, leading to a number of physiological and behavioral changes. Research conducted in both animals and humans has focused on how ecstasy use affects systems or functions in which serotonin has a regulatory role including mood, sleep and circadian rhythms. In this paper we review the evidence with respect to changes in sleep and circadian rhythms following ecstasy use. Studies of the subjective measurement of sleep have suggested that there are changes in sleep quality and duration following ecstasy use, while research utilizing objective measures including polysomnography has highlighted changes in sleep architecture following ecstasy use. Collectively these findings suggest that there are con...

Sequential amplitude variations in alpha band component in human electroencephalograms during sleep onset

Sleep and Biological Rhythms — Fri, 01 Jul 2011 04:00:00 +0100

AbstractThe purpose of this research is to elucidate the amplitude variations of alpha band component in human electroencephalographic records during the transition between wakefulness and stage 1 sleep. The records from 16 adult male subjects were mathematically analyzed in successive 3‐s epochs using a unique method of calculation (RLSSR). Amplitude variations are described herein. (i) General amplitudes are high during wakefulness and low during stage 1 sleep. Irregular fluctuations in amplitude are superimposed on these two levels. (ii) A large, steep, characteristic decline occurs during wakefulness. Two EEG patterns at the bottom of the decline represent arousal and EEG in stage 1 sleep, and these are referred to as big‐decline‐w and big‐decline‐s. The transition between th...

A variable‐number tandem repeat polymorphism in PER3 is not associated with chronotype in a population with self‐reported sleep problems

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

We examined whether a variable‐number tandem repeat (VNTR) polymorphism in the circadian clock gene PER3 was associated with subjective ratings of sleep and diurnal preference in a Romanian population with high levels of self‐reported sleep problems. Individuals, self‐reporting to their GP for sleep disturbances, completed a battery of validated scales that assess the presence of insomnia, sleep quality and diurnal preference and had their PER3 VNTR genotype determined. We found no significant differences in chronotype, sleep quality or other psychometric measures according to PER3 VNTR and conclude that diurnal preference or self‐reported sleep measures are not associated with PER3 genotype in this population. (Source: Sleep and Biological Rhythms)

Effect of post‐learning sleep versus wakefulness on advantageous decision‐making: A preliminary study

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

This study evaluates the effect of sleep on learning‐based decision‐making. Twenty‐four healthy volunteers were allocated randomly to two groups: a sleep group and a wake group. A modified Iowa gambling task was administered before and after a 12‐h period in which the sleep group slept about 8 h and the other group remained awake. The two groups' advantageous decision‐making during the initial learning phase did not differ, but the advantageous choices of the sleep group improved more than that of the wake group after the 12‐h period, suggesting that sleep may have facilitated and/or retained advantageous decision‐making. (Source: Sleep and Biological Rhythms)

Comparison of dream anxiety and subjective sleep quality between chronotypes

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

In this study, we aimed to investigate the relationship between sleep quality, dream anxiety, and chronotypes. A sample of 264 university students, aged between 17 and 26 years, completed the Morningness–Eveningness Questionnaire, the Pittsburgh Sleep Quality Index, and the Van Dream Anxiety Scale for assessing nightmare frequency and the dream anxiety caused by frightening dreams. Main findings indicated that evening‐type individuals were significantly more likely to suffer from poor sleep quality, daytime dysfunction, nightmares, and nightmare‐related disturbances as compared to either intermediate‐ or morning‐type individuals. Previous studies have pointed out the possible connections of irregular sleep–wake habits and circadian dysregulation with a tendency to reveal even...

Nocturnal polysomnographic characteristics of pediatric narcolepsy

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

AbstractThe aim of this study was to describe the polysomnographic features of childhood‐onset narcolepsy. A retrospective review was performed on children with narcolepsy. The polysomnogram findings were compared with reference values obtained from normative data in the general population. Narcolepsy subjects had a mean initial sleep latency of 10.9 min on nocturnal PSG, which was shorter by a mean of 18 min than corresponding values from normative data (P < 0.001). Short initial REM latency on nocturnal PSG correlated with the number of SOREMPs on MSLT in subjects with narcolepsy (P= 0.007). These findings may assist in the clinical diagnosis of narcolepsy. (Source: Sleep and Biological Rhythms)

Epileptic activity in mesial frontal cortex in nocturnal paroxysmal dystonia

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

We report the case of NPD arising from the mesial frontal lobe detected by subdural electrodes. A 25‐year‐old woman had daily NPD seizures. Her MRI showed no abnormalities. However, ictal single‐photon emission computed tomography revealed hyperperfusion of the bilateral mesial frontal lobes. We implanted subdural electrodes and found ictal onset arising from the bilateral anterior mesial frontal cortices synchronously. Partial callosotomy reduced her symptoms without any neurological deficit. (Source: Sleep and Biological Rhythms)

Sleep evaluation by a newly developed PVDF sensor non‐contact sheet: a comparison with standard polysomnography and wrist actigraphy

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

AbstractPolysomnographic (PSG) recording of multiple physiological measures remains the gold standard for sleep assessment in both basic and clinical human sleep research. However, PSG requires many unnatural conditions that can influence sleep phenomena. Recently, non‐contact sheet sensors (SS) have been developed for sleep evaluation. Sheet sensor technology provides advantages over existing minimally intrusive devices used to analyze sleep‐related behavior, such as wrist actigraphy (WA), beginning with freedom from attachment to any probes or devices. Current SS measures additionally include two physiological measures – heart rate (HR) and respiration rate (RR). To test the validity of SS analyses, we performed simultaneous recordings of SS and standard PSG in thirteen healthy adu...

Wake–REM sleep transitions for measuring REM sleep disturbance: Comparison between narcolepsy, idiopathic hypersomnia and healthy controls

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

This study tested a well‐known but as yet nonoperationalized means for measuring REM sleep disturbance in patients with narcolepsy at night. We retrospectively analyzed polysomnographies of patients with narcolepsy with cataplexy (n= 18), narcolepsy without cataplexy (n= 12), idiopathic hypersomnia (n= 22) and healthy controls (n= 33) with regard to the number of wake–REM sleep transitions as a measurement for REM sleep disturbance at night. We found a significantly higher number of transitions between wake and REM sleep (14.17 ± 2.00) in patients with narcolepsy with cataplexy than in healthy controls (3.70 ± 1.00; p < 0.001) and patients with idiopathic hypersomnia (5.36 ± 1.00; p= 0.001). These results confirm previous findings that REM sleep disturbance is a specific phenomen...

Melatonin and sleep effects on health, behavior problems and parenting stress

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

AbstractIn children with sleep‐onset insomnia and delayed dim‐light melatonin onset, melatonin treatment not only improves sleep but also health, behavior and parenting stress. The aim of the present study was to see whether the latter effects are dependent on the direct effects on sleep. Data come from 41 children (24 boys, 17 girls; mean age = 9.43 years). They entered melatonin treatment (1–5 mg per day) for three weeks, then discontinued treatment by first taking a half dose for one week, and then stopped completely for another week. Sleep was measured with sleep diaries filled in by parents and with actometers. We found a positive effect of actual sleep duration on health but this disappeared after discontinuing treatment. We also found that melatonin treatment decreased beh...

Summary of SBR in 2010

Sleep and Biological Rhythms — Thu, 30 Jun 2011 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Positional therapy for the reduction of obstructive sleep apnea

Sleep and Biological Rhythms — Tue, 14 Jun 2011 23:00:00 +0100

AbstractPositional obstructive sleep apnea (OSA) is defined as a 50% reduction in the apnea–hypopnea index (AHI) during non‐supine sleep position. Positional OSA is more common in patients with mild to moderate OSA than in patients with severe OSA. The aim of this study was to assess the efficacy of positional therapy using a recently developed vest device for positional OSA. Fourteen participants with mild to moderate positional OSA were included. To evaluate the efficacy of the vest, changes in OSA observed between baseline and experimental polysomnography were assessed. The adverse event rate and subject satisfaction were also estimated. The AHI was lower in the experimental examination, with a value of 9.3 ± 8.3, than in the control examination, with a value of 22.8 ± 9.3 (P <...

Reflex testing reveals circadian variation of spinal excitability in restless legs syndrome patients

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

AbstractRestless legs syndrome (RLS) is a condition characterized by night‐time exacerbation of symptoms, suggesting a possible circadian aetiology. It is hypothesised that RLS is caused by a central deficiency of dopamine causing spinal hyperexcitability. The study objective was to compare spinal reflex responses in RLS patients at two different times and with healthy participants. Standard electromyographic (EMG) techniques were used to quantify patellar and H‐reflexes in RLS patients (n= 11) and matched control subjects (n= 9). Kinematic analysis was performed on patellar reflexes to measure knee angular velocity and displacement. Both reflexes were tested in the evening and the following morning. RLS patients had a significantly attenuated evening quadriceps EMG amplitude during pa...

Questionnaire‐based evidence of association between sleepiness while driving and motor vehicle crashes that are subjectively not caused by falling asleep

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

This study revealed an association between MVCs and sleep problems or subjective sleepiness during driving among the respondents. In particular, sleepiness while driving was associated not only with MVCs caused by falling asleep but also with MVCs that were subjectively assessed as not being caused by falling asleep, suggesting that suppression of sleepiness while driving contributes to MVC prevention, irrespective of the occurrence of falling asleep. (Source: Sleep and Biological Rhythms)

Corrigendum

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Increased rate of traffic law infringements during on‐road metropolitan driving in obstructive sleep apnea patients

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

AbstractThe aim of this study was to compare metropolitan on‐road driving performance in patients with severe obstructive sleep apnea (OSA) and healthy age‐matched controls. A driving assessor–based on‐road driving test was performed at 2.00 pm in severe OSA patients and age‐matched healthy controls. Main outcome measures included passing or failing the test, occurrence of minor traffic faults (e.g. not indicating, late braking, mirror checking) and traffic law infringements (e.g. failing to stop or give way, speeding). Compared to controls, there was no evidence of gross driving impairment or higher driving test failure rate in OSA patients. However, OSA patients demonstrated ∼60% more traffic law infringements (11.0 ± 1.8 versus 6.8 ± 1.0% of general driving tasks, p= 0.024...

The effect of osteoporosis on self‐report sleep quality in postmenopausal women

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

AbstractWe aimed to show the effect of osteoporosis on sleep quality in 59 postmenopausal women. The participants' bone‐mineral density levels were measured by dual‐energy X‐ray absorptiometry (DEXA). According to their DEXA results, participants were divided into two groups as osteoporotics and controls. The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. Fourteen osteoporotic women (43.8%) and four controls (14.8%) were “poor” sleepers (p < 0.05). Postmenopausal women with osteoporosis scored greater on the “sleep latency” and “sleep duration” components of PSQI than controls. According to the findings of our study, osteoporosis is a risk factor for poor sleep quality in postmenopausal women. (Source: Sleep and Biological Rhythms)

Narcolepsy due to Parkinson's disease with a decrease in cerebrospinal‐fluid orexin: a case report

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

AbstractA 57‐year old man became affected by excessive daytime sleepiness. Thereafter, he had difficulty in moving his left limbs and began to walk slowly. He had no particular past or family history. He had taken no medications. Neurologically, Parkinsonism was present. Sleep examinations revealed that the diagnostic criteria of narcolepsy without cataplexy were fulfilled. The orexin level in the cerebrospinal fluid (CSF) was undetectable (<40 pg/mL). HLA DR2 was negative. These factors led to a diagnosis of narcolepsy due to Parkinson's disease (PD). This is the first clear case of narcolepsy due to PD presenting a decreased CSF‐orexin level. (Source: Sleep and Biological Rhythms)

New onset and natural remission of excessive daytime sleepiness and its correlates among high‐school students

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

AbstractExcessive daytime sleepiness (EDS) is highly prevalent among high‐school students, and preventative measures against it are essential for promotion of school health. With the aim of studying both the onset and amelioration of EDS and the factors that can predict these changes during the period at high school, we conducted a series of longitudinal surveys using self‐administered questionnaires. Surveys of students from three private high schools in Tokyo were conducted three times in November of each year, starting in 2007, when the subjects were in the 10th grade, and ending in 2009, when they were in the 12th grade. Of 1198 eligible students, 865 (effective response rate, 72.75%: 472 boys, 393 girls) were included in the analysis. The Japanese version of the Epworth Sleepiness...

Evaluation of a commercially available automated sleep staging tool in healthy infants

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

This study aims to evaluate the accuracy of this sleep staging system in healthy infants. Polysomnograms from 32 healthy infants were obtained from the CHIME dataset. Sleep staging was performed using the Pneumo mode of the ALICE5 package. Each polysomnogram was then re‐staged by an experienced pediatric sleep physician. The agreement rate and the kappa agreement rate between the manual sleep scoring and the automated sleep scoring were calculated. The mean agreement rate was 74.6% (SD = 10%), and the kappa agreement rate was κ= 0.558 (SD = 0.17). While the mean agreement rates are comparable with agreement rates between human scorers, the intra‐subject variability in performance means that the ALICE5‐generated automated sleep staging should be manually validated. (Source: Sleep and...

A sheet‐type device for home‐monitoring sleep apneas in children

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

This study was performed to clarify the usefulness of SD‐101 in detecting SAS in children. The infant (0–12 years old) from whom they consulted Sleep Disorders Center or otorhinolaryngology at Aichi Medical University hospital and SAS had been doubted was targeted between October 2005 and November 2009. The inspection was executed using PSG together with SD‐101 under hospitalization and using another simplified device (LS‐300) with SD‐101 at house. The analysis of SD‐101 was done by using software for adults and added to the manual correction. SD‐101 judged apnea‐hypopnea when the respiratory pressure changes decrease. The correlation was admitted in AHI of 31 examples that used PSG together with SD‐101 (R2 = 0.87). The cases who had used LS‐300 together with SD‐1...

Clinical significance and management of insomnia

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

AbstractSeveral epidemiological studies have shown that more than 20% of the general adult population has symptoms of insomnia, but only about 5% of them are receiving treatment for the symptoms. Most general physicians and patients seem to be unaware of both the potential morbidity associated with insomnia and the importance of sleep health. In addition, most people having sleep problems do not tell their primary physicians about the problems, while about 70% of physicians do not ask their patients about the existence of sleep problems. Sleep disorders have been reported to underlie the development and deterioration of several comorbid diseases such as hypertension, cardiovascular diseases, diabetes and depression. Thus, we performed a systematic review of the relationship between insomni...

A remembrance of the late Professor Teruo Okuma, M.D., Ph.D

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Welcome to the Worldsleep2011 meeting in Kyoto, Japan

Sleep and Biological Rhythms — Thu, 31 Mar 2011 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Do bright‐light shock exposures during breaks reduce subjective sleepiness in night workers?

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

This study evaluates the effects of bright‐light exposure (BL) on subjective sleepiness during night work. Ninety night workers who have more than a year's experience at a metallurgy production plant volunteered to participate in this clinical pilot study. Workers were divided into two groups and every group was exposed to either bright light (2500–3000 lux) or normal light (300 lux) during break times at night for two consecutive nights. Fifteen‐minute breaks were initiated at 22.00 h (before starting work) 24.00 h, 02.00 h and 04.00 h. The range of subjective sleepiness was assessed by the Stanford Sleepiness Scale (SSS) at 23.00 h, 01.00 h, 03.00 h and 05.00 h. We used SPSS 11.5 for data analysis. The result demonstrated that there were significant differences ...

Durability, safety, ease of use and reliability of a type‐3 portable monitor and a sheet‐style type‐4 portable monitor

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

We examined these factors with a type‐3 (cardio‐respiratory) PM and a sheet‐style type‐4 PM in unattended home settings. A cross‐sectional survey was conducted on male employees of a wholesale company in Osaka, Japan (n= 139, age = 44.4 ± 8.36 years). Participants used either of the two PMs on the second and third nights and both of the PMs on the fourth nights. A self‐administered questionnaire and actigraphy were used to analyze ease of use and sleep quality, respectively. No safety problems were reported. A few repairs were needed only for the type‐3 PMs. The type‐4 PM was more inconvenient to bring home (type 3: 15.1%; type 4: 68.3%). The type‐3 PM was more inconvenient to use (type 3: 71.2%; type 4: 0.7%) and more uncomfortable to use (type 3: 81.3%; type 4: 9.4%)...

Melatonin protects mice with intermittent hypoxia from oxidative stress‐induced pancreatic injury

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

We examined whether oxidative stress‐induced pancreatic injury could be reversed by the antioxidant melatonin (MEL) in male C57BL/6J mice with intermittent hypoxia(IH). Male C57BL/6J mice were randomly divided into four groups: a vehicle‐treated normoxic group (CON), a melatonin‐treated normoxic group (MEL), a vehicle‐treated intermittent hypoxic group (IH) and a melatonin‐treated intermittent hypoxic group (IH+MEL). The vehicle (2% ethanol in normal saline) or melatonin (10 mg/kg) was intraperitoneally administered daily for 2 weeks, 30 min before normoxia (intermittent air) or IH exposure. Insulin tolerance, plasma insulin levels, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, glutathione (GSH) concentrations, β‐cell apoptosis, and mRNA expression of ...

Overview of sleep and sleep medicine in Asian countries

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractWhile there are a number of sleep medicine and sleep research publications in Asia, and their quality is increasing each year, the actual situation of sleep disorders in the general population still remains an issue of major concern. Scientists and medical doctors believe that, for the first time in history, the general lack of sleep could lead to a diminution of life expectancy. It is also known that, as people are working more and more and are more tired, they are more likely to become victims of accidents. Most of the time these incidents have little gravity, but sometimes they can cost thousands of innocent lives or contribute to disasters such as the Chernobyl nuclear plant explosion or the Bhopal gas tragedy. Based on the Asian Sleep Research Society Summit and Symposium Roun...

Genetic dissection of neural circuitry regulating behavioral state using conditional transgenics

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractConditional transgenic animals are useful tools that can be used to determine the detailed anatomic and molecular bases of sleep–wake regulation. This short review highlights some of the most recent molecular biological technologies for “systems‐level” sleep research in freely behaving animals. These technical advances include a wide range of approaches from conditional deletion of genes based on the Cre/loxP technology to RNA interference to the in vivo reversible manipulation (silencing and activation) of neurons by tetracycline‐controlled tetanus neurotoxin or the expression of genetically modified receptor‐channel complexes. In combination with these advanced genetic techniques, adeno‐associated viral vectors (AAVs) represent a versatile gene delivery system for s...

Sleep‐active cells in the cerebral cortex and their role in slow‐wave activity

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractWe recently identified neurons in the cerebral cortex that become activated during sleep episodes with high slow‐wave activity (SWA). The distinctive properties of these neurons are the ability to produce nitric oxide and their long‐range projections within the cortex. In this review, we discuss how these characteristics of sleep‐active cells could be relevant to SWA production in the cortex. We also discuss possible models of the role of nNOS cells in SWA production. (Source: Sleep and Biological Rhythms)

Basal forebrain regulation of cortical activity and sleep‐wake states: Roles of cholinergic and non‐cholinergic neurons

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractThe basal forebrain (BF) plays an important role in regulating cortical activity and sleep/wake states. Both cholinergic and non‐cholinergic neurons of the BF project to the cerebral cortex and hippocampus, whereas the hypothalamus and brainstem nuclei are mostly innervated by non‐cholinergic BF neurons. Neurons in the BF show various discharge profiles in relation to cortical activity and behavioral states and are differentially modulated by neurotransmitters of other sleep/wake regulatory neurons. Recent technical advances have made it possible to correlate discharge profiles of single BF neurons during sleep/wake states with their neurochemical phenotypes, and to make selective lesions of certain cell types. The goal of this review is to summarize the current knowledge of th...

What are the mechanisms activating the sleep‐active neurons located in the preoptic area?

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractThe purpose of this review is to outline the mechanisms responsible for the induction and maintenance of slow‐wave sleep (SWS, also named non–rapid eye movement or non‐REM sleep). The latest hypothesis on the mechanisms by which cortical activity switches from an activated state during waking to a synchronised state during SWS is presented. It is proposed that the activated cortical state during waking is induced by the activity of multiple waking systems, including the serotonergic, noradrenergic, cholinergic and hypocretin systems located at different subcortical levels. In contrast, the neurons inducing SWS are mainly localized in the ventrolateral preoptic (VLPO) and median preoptic nuclei. These neurons use the inhibitory neurotransmitter gamma‐aminobutyric acid (GABA)...

Insomnia, hypersomnia and coma in animal models and their clinical implications

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractEconomo observed in 1930 that many cases of lethargy begin with a severe insomnia and fever followed by a long‐lasting hypersomnia. We confirmed this evidence in animal cases where chemical lesions of the preoptic region resulted in severe insomnia accompanied with fever. Moreover, a subsequent pharmacological inhibition of neuronal activity of the posterior ventrolateral hypothalamus caused transient hypersomnia in these insomniac animals. However, vigilance states of the experimental animals returned to normal after several weeks, suggesting that the irreversible Economo's lethargy may be due to the damage of passing fibers in the ventral hypothalamus. Similarly, chemical lesions of neurons of the midbrain reticular formation did not induce coma nor hypersomnia, which is incons...

Narcolepsy, orexins and respiratory regulation

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractNarcolepsy is a debilitating sleep disorder characterized by excessive daytime sleepiness, cataplexy and intrusive rapid–eye movement sleep. Deficits in endogenous orexins are a major pathogenic component of the disease. This disorder is also associated with the gene marker HLADQB1*0602. Orexins as hypothalamic neuropeptides have multiple physiological functions, and their primary functions are regulation of the sleep–wake cycle and feeding. Evidence from animal studies using orexin knockout mice and focal microdialysis of an orexin receptor antagonist at the retrotrapezoid nucleus and medullary raphe in rats demonstrated that orexins also contribute to respiratory regulation in a vigilance state–dependent manner, as animals with orexin dysregulation have attenuated hypercapn...

Interaction between sleep mechanisms and orexin neurons

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractOrexin is a neuropeptide that plays a highly important role in mechanisms that regulate sleep/wake states. Lack of the orexin gene or orexin‐producing neurons (orexin neurons) results in narcolepsy in several mammalian species, suggesting that orexin is an important factor for the maintenance of wakefulness. Constitutive, ectopic expression of orexin in transgenic mice resulted in severe fragmentation of non–rapid eye movement sleep, along with abnormal muscle tone regulation during REM sleep, suggesting that activity of orexin neurons should be appropriately decreased during sleep to maintain consolidated sleep states. This review will discuss the mechanisms by which the orexin system is regulated during sleep. (Source: Sleep and Biological Rhythms)

Key roles of the histaminergic system in sleep–wake regulation

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractHistamine plays an important role in mediating wakefulness in mammals. Based on the findings from gene‐manipulated mice, we provide several lines of evidence showing the roles of the histaminergic system in the somnogenic effects of prostaglandin (PG) D2 and adenosine, and in the arousal effects of PGE2 and orexin. PGD2 activates DP1 receptors (R) to promote sleep by stimulating them to release adenosine. The released adenosine activates adenosine A2AR and subsequently excites the ventrolateral preoptic area (VLPO), one of the sleep centers in the anterior hypothalamus. VLPO neurons then send inhibitory signals to downregulate the histaminergic tuberomammillary nucleus (TMN), which contributes to arousal. A1R is expressed in histaminergic neurons of the rat TMN. Adenosine in the ...

The ATP–cytokine–adenosine hypothesis: How the brain translates past activity into sleep

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractTumor necrosis factor alpha (TNF), interleukin‐1 beta (IL1), and other cytokines are involved in non‐rapid eye movement sleep (NREM) regulation under physiological and inflammatory conditions. Brain levels of IL1 and TNF increase with prolonged wakefulness. Injection of exogenous IL1 or TNF, mimicking sleep loss, induces sleepiness, excess sleep, fatigue, poor cognition, and enhanced sensitivity to pain. These symptoms characterize the syndrome associated with sleep loss. Extracellular ATP released during neuro‐ and glio‐transmission, acting via purine P2 receptors on glia, releases IL1 and TNF. This extracellular ATP mechanism may provide an index of activity used by the brain to keep track of prior wakefulness. Prolonged wakefulness is associated with enhanced neuronal ac...

Physiological and pathophysiological roles of adenosine

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractAdenosine is a candidate sleep substance. It can be both a distress signal of importance in pathology and a physiological regulator. Key factors in determining which of these possibilities pertain are: (i) the number of receptors expressed, and (ii) the mechanisms that establish extracellular adenosine levels. The roles of adenosine are studied by means of antagonists and/or animals (mostly mice) with targeted deletions of receptors or enzymes involved in adenosine metabolism. Whereas adaptive changes in the genetically modified mice can occur for the physiologically important effects, such adaptive changes are less likely to occur in situations where adenosine acts as a distress signal. The relevance to sleep will be covered only in general terms in this review and will be covered...

Adenosine as a sleep factor

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractWhat puts us to sleep? This question has bothered the mankind for thousands of years, but we still have no definite answer. After abandoning philosophical and religious explanations, science has adopted this question and started to examine it with experimental methods. Two early pioneers in this field, Dr. Ishimori from Japan and Drs. Pieron and Legendre from France developed the concept of hypnotoxin – a factor that accumulates during waking and puts animals and humans to sleep. They were able to show that, indeed, during deprivation of sleep, something accumulates in body – something that can be removed and will induce sleep in another individual. Later research has identified many substances that affect sleep. One of them is adenosine, which fulfils the criteria of a physiol...

Prostaglandin D2 and adenosine as endogenous somnogens

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractProstaglandin D2 (PGD2) is the most potent endogenous sleep‐promoting substance thus far reported. We have extensively studied its action mechanism at the molecular level. PGD2 is produced by lipocalin‐type PGD synthase, which is dominantly localized in the leptomeninges, choroid plexus, and oligodendrocytes in the brain; and it is secreted into the cerebrospinal fluid and stimulates DP1 receptors localized in the arachnoid membrane of the ventral surface from the basal forebrain to the hypothalamus to increase the extracellular concentration of adenosine as a paracrine sleep‐promoting molecule. Adenosine diffuses into the brain parenchyma, suppresses cholinergic arousal neurons in the basal forebrain via adenosine A1 receptors, activates sleep‐active neurons in the ventrol...

Humoral mechanisms of sleep–wake regulation: Historical review of prostaglandin D2 and related substances

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

AbstractSleep is perhaps one of the most important and yet least understood of the physiological functions of the brain. Sleep is essential for life, but we still cannot answer even the simplest questions about sleep, such as “what is sleep?,”“why do we need to sleep?,” and most importantly, “where and how are sleep and arousal regulated?” In the mean time, the number of sleep‐disorder patients has recently been increasing exponentially and now exceeds more than 25% of the total population in most countries. More than 107 different sleep disorders have now been described, but in most instances, their etiologies are not yet clearly understood, simply because basic sleep science research has really only just begun. In the early 1980s, my colleagues and I at Kyoto University ser...

Sleep substances, sleep architecture, and sleep sociology: Centennial anniversary of the first discovery of sleep substances by Kuniomi Ishimori

Sleep and Biological Rhythms — Tue, 01 Feb 2011 00:00:00 +0100

(Source: Sleep and Biological Rhythms)

Lack of association between orexin receptor gene polymorphisms and obstructive sleep apnea syndrome in Japanese

Sleep and Biological Rhythms — Sat, 01 Jan 2011 00:00:00 +0100

In conclusion, there are some reports evaluating the plasma level of orexins in patients with OSAS compared to normal subjects. However, the role of orexin genes in the pathogenesis of OSAS has yet to be evaluated. This candidate gene study shows that orexin receptor gene polymorphisms are unlikely to be associated with OSAS in Japanese people. (Source: Sleep and Biological Rhythms)

Epidemiology of restless legs syndrome in the Iranian population

Sleep and Biological Rhythms — Sat, 01 Jan 2011 00:00:00 +0100

AbstractAs one of the most common neurological disorders, restless legs syndrome (RLS) is generally underdiagnosed and undertreated. Considering the lack of knowledge regarding the world‐wide epidemiology of this common neurological disorder, we carried out a study to estimate the distribution of RLS in Isfahan, a city in the center of Iran. During the one‐month period from 8 August 2007 to 8 September 2007, patients older than 18 years referred to eight neurology clinics were asked to fill out two questionnaires. The first questionnaire was derived from the diagnostic criteria for RLS outlined by the International RLS Study Group (IRLSSG). The second covered sociodemographic conditions and some other parameters concerning the clinical characteristics of RLS. Of the 2099 responding pat...

Selection of optimal epoch duration in assessment of rodent sleep–wake profiles

Sleep and Biological Rhythms — Sat, 01 Jan 2011 00:00:00 +0100

This study was designed to find the optimal EEG epoch duration that accurately reveals the sleep–wake profiles of animals and relieve researchers of the laborious analysis of rodent sleep–wake parameters. We analyzed mouse and rat EEG signals with commonly used epoch durations (4, 8, 10, 20, and 30 s) and compared the resulting sleep–wake profiles in terms of amounts of sleep and wakefulness, number and duration of episodes, number of sleep–wake stage transitions, and EEG power spectra. There were no statistical differences in the amount and EEG power density of wakefulness, rapid eye movement (REM) and non‐REM sleep among the 5 epoch durations we used. However, the shorter the epoch, the more numerous the stage transitions and the larger the episode number. The purpose of an e...

How and Why? The lab versus the field

Sleep and Biological Rhythms — Sat, 01 Jan 2011 00:00:00 +0100

(Source: Sleep and Biological Rhythms)

Modeling fatigue‐related truck accidents: Prior sleep duration, recency and continuity

Sleep and Biological Rhythms — Sun, 28 Nov 2010 00:00:00 +0100

This study investigated the ability to predict fatigue‐related accidents using: (a) the a priori model; (b) an optimized model (manipulating X and Y); (c) models with continuous or split sleep; (d) HOS indicators; and (e) combined PSW and HOS models. Sleep and work histories were collected from 107 truck accidents (male drivers, aged 23–66 y), of which 62 had a probable cause of fatigue. The a priori model correctly classified 65%, and the optimized model (6.5 h in the prior 24 h and 8 h in the prior 48 h) nearly 71% of accidents. A simplified model of 6.5 h continuous sleep in the prior 24 h correctly classified nearly 75%. HOS indicators correctly classified <60% and combined models, approximately 73%. PSW or combined PSW/HOS approaches may more effectively manage fa...

Stress coping behaviors and sleep hygiene practices in a sample of Japanese adults with insomnia

Sleep and Biological Rhythms — Fri, 01 Oct 2010 00:00:00 +0100

This study examined the characteristics of behaviours for coping with stress and sleep hygiene practices utilized by adult people with insomnia. Self‐administered questionnaire data from a representative sample of 24 551 adults (completed in 2000) were analyzed. Participants reported insomnia symptoms present during the last 1‐month period, answering 11 items on physical and psychological conditions, 7 items on problem‐solving and emotion‐focused coping behaviors in response to stress (SCBs), 5 items on measures taken to ensure adequate sleep (SHPs), and the Center for Epidemiologic Studies Depression Scale (CES‐D). Those presenting with insomnia symptoms accompanied by daytime complaints were defined as having insomnia. Multivariable logistic regressions were performed with se...

Preliminary test for the Chinese version of the Morningness–Eveningness Questionnaire

Sleep and Biological Rhythms — Fri, 01 Oct 2010 00:00:00 +0100

AbstractThe original English Morningness–Eveningness Questionnaire (MEQ) was translated into Chinese, and the circadian rhythmicity of 188 healthy Chinese subjects was tested using this version of the MEQ. We assessed the reliability and validity of the Chinese version and determined the cut‐off points. In the Chinese version, 19 items were divided into two dimensions (i.e., sleep phase and time of greatest efficiency), and the cut‐off points were determined to be the following: definitely evening type (14–46), moderately evening type (47–52), neither type (53–64), moderately morning type (65–69), and definitely morning type (70–86). Additionally, the Cronbach α coefficient was determined to be 0.769, which is satisfactory. The Chinese version of the MEQ has good psychomet...

A meta‐analysis on the treatment effectiveness of cognitive behavioral therapy for primary insomnia

Sleep and Biological Rhythms — Fri, 01 Oct 2010 00:00:00 +0100

AbstractPrevious meta‐analyses have shown the effectiveness of cognitive behavioral therapy for insomnia (CBT‐I). However, conclusive information about therapeutic effects (especially during follow‐up), effect sizes of objective sleep parameters and self‐rating scales, and the problem of publication bias has not been obtained. We conducted a meta‐analysis focusing on these issues. We identified 14 randomized controlled studies published between 1990 and 2009 that fulfilled our selection criteria. Intra‐group comparison of CBT‐I and comparison between CBT‐I and control groups were performed on these studies. The intra‐group comparison revealed that the effect sizes of CBT‐I for subjective sleep variables from sleep diaries were medium to large at the end point of treatme...

Morningness‐eveningness and behavioural problems in adolescents

Sleep and Biological Rhythms — Fri, 01 Oct 2010 00:00:00 +0100

AbstractIndividuals differ in their biological rhythms. Some persons are morning orientated, preferring morning hours for intellectual and physical activities, and others are evening orientated. Previous work on adults revealed correlations between this morningness–eveningness construct and different aspects of mental health and well‐being; for example, depression and seasonal affective disorders were related to eveningness. We hypothesise that morningness–eveningness may be associated with behavioural variables as measured by Goodman's Strength and Difficulties Questionnaire (SDQ). 150 girls and 150 boys form German secondary schools participated in this study. We used the Composite Scale of Morningness (CSM) to assess chronotype and the SDQ to assess behavioural difficulties. CSM s...

Excessive daytime sleepiness and sleep behavior among Japanese adolescents: A nation‐wide representative survey

Sleep and Biological Rhythms — Thu, 30 Sep 2010 23:00:00 +0100

Abstract (Source: Sleep and Biological Rhythms)

Structure validity of the Pittsburgh Sleep Quality Index in renal transplant recipients: A confirmatory factor analysis

Sleep and Biological Rhythms — Thu, 30 Sep 2010 23:00:00 +0100

Abstract (Source: Sleep and Biological Rhythms)

Sleep‐improving effects of the aromatic compound heliotropin

Sleep and Biological Rhythms — Thu, 30 Sep 2010 23:00:00 +0100

Abstract (Source: Sleep and Biological Rhythms)

Memantine also effective in a patient suffering from narcolepsy?

Sleep and Biological Rhythms — Thu, 30 Sep 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

New Horizon

Sleep and Biological Rhythms — Thu, 30 Sep 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Author index

Sleep and Biological Rhythms — Tue, 21 Sep 2010 08:00:14 +0100

(Source: Sleep and Biological Rhythms)

Poster presentations

Sleep and Biological Rhythms — Tue, 21 Sep 2010 08:00:12 +0100

(Source: Sleep and Biological Rhythms)

Oral presentations

Sleep and Biological Rhythms — Tue, 21 Sep 2010 08:00:10 +0100

(Source: Sleep and Biological Rhythms)

New investigator

Sleep and Biological Rhythms — Tue, 21 Sep 2010 08:00:08 +0100

(Source: Sleep and Biological Rhythms)

Invited speakers

Sleep and Biological Rhythms — Tue, 21 Sep 2010 08:00:07 +0100

(Source: Sleep and Biological Rhythms)

Not all adolescents are sleep deprived: A study of rural populations

Sleep and Biological Rhythms — Tue, 21 Sep 2010 08:00:01 +0100

Abstract (Source: Sleep and Biological Rhythms)

Acute sleep restriction does not affect declarative memory in 10-year-old girls

Sleep and Biological Rhythms — Wed, 21 Jul 2010 23:00:00 +0100

The study aim was to determine the effects of sleep restriction (5 h of time in bed) compared with 10 h of sleep opportunity on declarative memory function in young children. Fourteen girls attended a sleep laboratory for three nights: adaptation, control, and restriction. The Auditory Verbal Learning Task (AVLT) measured declarative memory performance before and after sleep. No significant differences were found in performance between control and sleep restriction. Performance deteriorated in all delayed recall trials, with significant differences found between pre- and post-sleep trials in both conditions. Memory function in children, as measured by the AVLT, is not affected by acute sleep restriction. (Source: Sleep and Biological Rhythms)

Returning from night shift to day life: Beneficial effects of light on sleep

Sleep and Biological Rhythms — Wed, 21 Jul 2010 23:00:00 +0100

Subjects working a 12 h offshore night shift for 2 weeks normally adapt to the night shift and are out of synchrony when they return home to day life, with consequent problems of poor sleep. The aim of this study was to investigate the effectiveness of timed light treatment to hasten circadian adaptation and improve sleep after the night shift. Ten male shift workers worked 19.00[ndash]07.00 h (n= 4) or 18.00[ndash]06.00 h (n= 6) offshore shift schedules. They were assessed for the last 7 days of a 14 or 21 day offshore night shift and for the following 14 days at home. Either timed light treatment/sunglasses or no light treatment/no sunglasses were scheduled in a crossover design during days 1[ndash]5 after the nightshift, theoretically timed to advance the circadian system. Subjects comp...

Insomnia symptoms associated with hyperglycemia

Sleep and Biological Rhythms — Wed, 21 Jul 2010 23:00:00 +0100

In recent years, insomnia and short sleep duration have been reported to worsen glucose tolerance. Because only a few prospective studies have investigated this issue in Japan, various aspects have yet to be elucidated. Therefore, we conducted a 2-year prospective study of Japanese local residents in order to examine the association between the onset of glucose tolerance disorders and insomnia/short sleep duration. In 2005 and 2007, residents of a rural community in Aomori Prefecture, Japan, were sent a self-administered questionnaire, and peripheral blood samples were collected to measure their fasting plasma glucose levels. A total of 497 residents participated in both of the surveys. The incidence of hyperglycemia was calculated as the number of people who had had neither hyperglycemia ...

A new perspective on sleepiness

Sleep and Biological Rhythms — Wed, 21 Jul 2010 23:00:00 +0100

The aim of this investigation was to examine current methods for measuring sleepiness from a new perspective, highlighting different definitions of sleepiness that are being used, inadequacies of the current conceptual framework for thinking about sleep and wakefulness, and the different timescales used for measuring sleepiness. The currently used methods are briefly described. The results of different tests of sleepiness within the same subjects are then examined, first, using subjectively reported item-scores from the Epworth Sleepiness Scale, and later, using mean sleep latencies in the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test. It is concluded that sleepiness, in the sense of sleep propensity, is not a single characteristic of each person. Measurements of slee...

Sleep is neither a passive nor an active phenomenon

Sleep and Biological Rhythms — Wed, 21 Jul 2010 23:00:00 +0100

According to traditional belief, prolonged wakefulness during the day is followed by brain rest at night in the form of sleep. This passive theory of sleep was replaced by the active sleep genesis concept, mainly after the realization that brain activity is only slightly reduced during sleep. There is now growing evidence to suggest that sleep is auto-regulatory and that it is not necessary to attribute sleep genesis to either an active or a passive mechanism. (Source: Sleep and Biological Rhythms)

Measuring sleep habits using the Sleep Timing Questionnaire: A validation study for school-age children

Sleep and Biological Rhythms — Wed, 07 Jul 2010 23:00:00 +0100

This study sought to validate the STQ for school-age children. Sixty-five children (20 boys, 45 girls), aged 11[ndash]16 years participated in this study. The participants wore wrist actigraphs, completed a 1-week sleep diary and the STQ. Analyses tested convergent validity between the STQ and actigraphy, and the STQ and sleep diaries. Correlations between STQ and actigraphy (r = 0.45[ndash]0.76, P < 0.001), and STQ and sleep diaries (r = 0.42[ndash]0.86, P < 0.001), were positive and significant for sleep onset and wake times. Correlations between STQ and actigraphy for sleep latency and wake after sleep onset (WASO) were very low (r < 0.10). In contrast, sleep latency was moderately and significantly correlated between STQ and sleep diary (r = 0.42, P < 0.001), and the correlation for WA...

Nightmare frequency is associated with subjective sleep quality but not with psychopathology

Sleep and Biological Rhythms — Tue, 06 Jul 2010 23:00:00 +0100

This study aimed to evaluate all known and hypothesized predictors for nightmare frequency measures in a population with frequent nightmares. A total of 666 Internet-recruited participants completed questionnaires on nightmares, sleep, and psychopathology, 146 of whom further completed a subsequent 7-day diary. In contrast to previous research, comparison of questionnaire- and diary-measured nightmare frequency revealed a significantly higher log-transformed nightmare frequency on the questionnaire: t(127) = 4.43; P < 0.001. No differences were found regarding the number of nights with nightmares, t(127) = 0.61; P= 0.54. Regression analyses showed that subjective sleep quality was the only variable significantly associated with nightmare frequency variables in the whole sample (R2adj betwe...

Sleep in patients with Chiari‐I malformations

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Relationship between snoring sound intensity and daytime blood pressure

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Stable inter‐individual differences in slow‐wave sleep during nocturnal sleep and naps

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Subjective and objective sleep in children and adolescents: Measurement, age, and gender differences

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Acute sleep restriction does not affect declarative memory in 10‐year‐old girls

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

Abstract (Source: Sleep and Biological Rhythms)

Measuring sleep habits using the Sleep Timing Questionnaire: A validation study for school‐age children

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

Abstract (Source: Sleep and Biological Rhythms)

Chronotherapeutics: An example of translational research for sleep and mood disorders

Sleep and Biological Rhythms — Wed, 30 Jun 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Adolescent sleep and fluid intelligence performance

Sleep and Biological Rhythms — Wed, 28 Apr 2010 23:00:00 +0100

This study examined relationships between adolescent sleep, fluid intelligence, and academic achievement. Participants were 217 adolescents (42% male) aged 13 to 18 years (mean age, 14.9 years; SD = 1.0) in grades 9[ndash]11. Fluid intelligence was predicted to mediate the relationship between adolescent sleep and academic achievement. Students completed online questionnaires of self-reported sleep, fluid intelligence (Letter Sets and Number Series), and self-reported grades. Total sleep time was not significantly related to fluid intelligence nor academic achievement (both P > 0.05); however, sleep difficulty (e.g. difficulty initiating sleep, unrefreshing sleep) was related to both (P < 0.05). The strength of the relationship between sleep difficulty and grades was reduced when fluid int...

Napping during the late-luteal phase improves sleepiness, alertness, mood and cognitive performance in women with and without premenstrual symptoms

Sleep and Biological Rhythms — Thu, 08 Apr 2010 23:00:00 +0100

The objective was to investigate the effects of a mid-afternoon nap during the late-luteal phase of the menstrual cycle on sleepiness, alertness, mood, cognitive performance, and subsequent nocturnal sleep among women with significant emotional/behavioral premenstrual symptoms compared to women with minimal symptoms. Following an adaptation sleep recording, 10 women with significant premenstrual symptoms and 9 women with minimal or no symptoms were recorded during one night in the follicular phase, and two nights during the late-luteal phase, -one after a nap of a maximum duration of 30 minutes, and another without a nap. Measures of sleepiness, alertness, mood, and cognitive performance were completed before, and at intervals after the nap and no nap sessions. Napping improved sleepiness,...

Oscillators entrained by food and the emergence of anticipatory timing behaviors

Sleep and Biological Rhythms — Thu, 08 Apr 2010 23:00:00 +0100

Circadian rhythms are adjusted to the external environment by the light[ndash]dark cycle via the suprachiasmatic nucleus, and to the internal environment of the body by multiple cues that derive from feeding/fasting. These cues determine the timing of sleep/wake cycles and all the activities associated with these states. We suggest that numerous sources of temporal information, including hormonal cues such as corticoids, insulin, and ghrelin, as well as conditioned learned responses determined by the temporal relationships between photic and feeding/fasting signals, can determine the timing of regularly recurring circadian responses. We further propose that these temporal signals can act additively to modulate the pattern of daily activity. Based on such reasoning, we describe the rational...

Joint effects of body mass index, exercise, and alcohol drinking on the development of snoring

Sleep and Biological Rhythms — Thu, 08 Apr 2010 23:00:00 +0100

Obesity is consistently reported to have a positive association with the development of habitual snoring. Whether lifestyle factors modify the association between body weight and the future risk of snoring has not been examined. In a prospective cohort study, we evaluated the association of lifestyle factors and body mass index (BMI) with the development of snoring. The study population (497 men and 670 women aged 40[ndash]69 years) were drawn from an ongoing population-based cohort. At baseline, all participants were free of cardiovascular disease and snoring at night. Information on lifestyle factors and snoring frequencies was obtained from interviewer-based questionnaires. During the 4-year follow-up, 533 participants reported new onset snoring. After adjusting for age, sex, and other ...

Timelessness in Sleep: Multidimensional Scope

Sleep and Biological Rhythms — Wed, 31 Mar 2010 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Restless legs syndrome and pregnancy in Kayseri, Turkey: A hospital based survey

Sleep and Biological Rhythms — Thu, 11 Mar 2010 00:00:00 +0100

The prevalence of restless legs syndrome (RLS) is low in the general population in Turkey. To assess the prevalence of RLS in pregnancy, a hospital-based survey assessing symptoms of RLS and other sleep problems was performed through face-to-face interviews and physical examination on 983 pregnant women from 11 hospitals in the two urban and four suburban areas of Kayseri, Turkey, at the time of delivery and 6 months after delivery. RLS is diagnosed clinically by means of the four essential criteria of the International RLS Study Group. A total of 103 women reported the occurrence of RLS symptoms during pregnancy, giving an RLS prevalence rate of 10.48%, with presence of symptoms more than three times per month, which decreased to 2.9% after 6 months. A significant relationship was observe...

Shift-work research: Where do we stand, where should we go?

Sleep and Biological Rhythms — Wed, 10 Mar 2010 00:00:00 +0100

Shift-work seriously affects the health and well-being of millions of people worldwide, and the number of shift workers is constantly rising (currently approximately 20% of the workforce). While some effects are acute, others lead to chronic syndromes that persist after retirement. Though health problems in shift workers are well established, we still do not properly understand the causal mechanisms underlying shift-work's effects on health. One reason may be the heterogeneity in shift-work research design and methodology, rendering comparison between studies difficult or even impossible. Shift-work also involves a multitude of interacting factors, and we do not yet fully understand many of these interactions. Interindividual differences between workers are central predictors for health. A...

Usp46, encoding a ubiquitin specific peptidase, is a quantitative trait gene underlying "behavioral despair" in mice

Sleep and Biological Rhythms — Wed, 10 Mar 2010 00:00:00 +0100

CS mice exhibit several distinct phenotypes of circadian behavioral rhythms and sleep properties. Because many mental illnesses are associated with abnormalities in the circadian rhythms and sleep pattern, we characterized the behavioral phenotypes in CS mice with a battery of behavioral tests. Among these phenotypes, we found that CS mice exhibit an extremely low immobility time in both the tail suspension test (TST) and forced swimming test (FST). To uncover the genetic basis for lower immobility time, we first performed quantitative trait locus (QTL) mapping using CS and C57BL/6J mice, which revealed significant QTLs on chromosomes (Chrs) 4 (FST) and 5 (TST and FST). To identify the quantitative trait gene on Chr 5, we narrowed the QTL interval to 0.5 Mb using several congenic and subco...

Temperature-insensitive reaction in the mammalian circadian clock

Sleep and Biological Rhythms — Fri, 11 Dec 2009 00:00:00 +0100

The striking feature of the circadian clock is its flexible yet robust response to various environmental conditions. A chemical-biological approach with 1260 pharmacologically active compounds identified "potent" compounds that markedly (>10 SD) lengthened the period. Most inhibited casein kinase I[epsilon] (CKI[epsilon]) phosphorylation of the PER2 protein. By examining period extending effect and PER2 degradation inhibition of the 10 potent compounds, we verified the CKI[epsilon]-dependent phosphorylation as a period-determining process. Moreover, the CKI[epsilon]-dependent phosphorylation was temperature-insensitive in living clock cells. This temperature-insensitivity was preserved in the CKI[epsilon]-dependent phosphorylation of a synthetic peptide in vitro. In addition, overexpressio...

Limits of single-cell autonomy in the suprachiasmatic nucleus

Sleep and Biological Rhythms — Tue, 08 Dec 2009 00:00:00 +0100

The suprachiasmatic nucleus (SCN) is the master circadian pacemaker in the mammalian brain, responsible for coordinating circadian (ca 24 h) rhythms throughout the body. When individual SCN neurons are dispersed in low density culture, they generate independent circadian oscillations in neuronal firing rate. This observation has led to the widely accepted conclusion that single SCN neurons are autonomous circadian oscillators. More recent studies using bioluminescence imaging to monitor rhythms of clock gene expression have indicated that fibroblasts, too, are autonomous circadian oscillators. But does this mean that the fibroblast should "replace the SCN as the in vitro model of choice"? On the contrary, the SCN is much more than a population of independent cellular oscillators. SCN funct...

Chronostatic adaptations in the liver to restricted feeding: The FEO as an emergent oscillator

Sleep and Biological Rhythms — Mon, 07 Dec 2009 00:00:00 +0100

We propose that the mammalian timing system is formed by constitutive clocks, such as the suprachiasmatic nucleus, and emerging clocks build up from the coordinated activity of peripheral oscillators, such as the food entrained oscillator (FEO). This timing system underlies a general regulatory process that modulates the set point of physiological variables in a periodic manner known as chronostasis. In contrast to the suprachiasmatic nucleus, the FEO is a distributed system formed by different brain areas such as the dorsomedial and ventromedial hypothalamus and the paraventricular thalamic nucleus, and peripheral organs such as the liver, adipose tissue, and skeletal muscle, and some endocrine glands. Central to the notion of FEO as an emerging oscillator is the establishment of a series...

Nocturnal premature ventricular complexes in a young woman with respiratory effort-related arousals

Sleep and Biological Rhythms — Tue, 01 Dec 2009 00:00:00 +0100

We report a young female with snoring and daytime sleepiness who exhibited frequent premature ventricular complexes (PVCs) primarily during non-rapid eye movement sleep. She was underweight and suspected to have respiratory effort-related arousal (RERA) based on polysomnographic data. The presence of autonomic instability and alternating conducting system provoked by repetitive markedly negative intrathoracic pressure was assumed to be precipitating PVCs. Follow-up polysomnography after oral appliance therapy showed reduced PVCs. The results suggest that a careful evaluation of polysomonographic data is warranted when RERA is suspected as an underlying mechanism for nocturnal PVCs even in non-obese patients. (Source: Sleep and Biological Rhythms)

Self-reported long sleep in older adults is closely related to objective time in bed

Sleep and Biological Rhythms — Tue, 01 Dec 2009 00:00:00 +0100

Although self-reported long sleep is associated with increased morbidity and mortality, little is known about the objective sleep patterns and daytime functioning of long sleepers, particularly those aged [ge]50 years. Our primary aim was to compare the objective and subjective sleep patterns of a sample (n= 35) of middle- to older-aged adults who reported sleeping [ge]8.5 h per night. A secondary aim was to characterize the mood and functioning of the sample. Over a 2-week period, sleep was recorded via actigraphy and a daily diary. Sleepiness was assessed daily. At the conclusion of the 2-week period, daytime sleepiness, mood, and quality of life were assessed. Measures of sleep and functioning were compared with available representative data. In the sample, actigraphic total sleep time ...

Practitioners of vipassana meditation exhibit enhanced slow wave sleep and REM sleep states across different age groups

Sleep and Biological Rhythms — Thu, 26 Nov 2009 00:00:00 +0100

Intense meditation practices influence brain functions in different ways and at different levels. Earlier studies have shown that meditation practices help to organize sleep[ndash]wake behavior. In the present study, we evaluated the sleep architecture of vipassana meditators across different age groups. Whole-night polysomnography was carried out in healthy male subjects between 30 and 60 years of age from control (n= 46) and meditation (n= 45) groups. They were further divided into younger- (30[ndash]39 years), middle- (40[ndash]49 years), and older-aged (50[ndash]60 years) groups. Sleep variables were evaluated from subjects who had a sleep efficiency index more than 85%. The sleep architecture of vipassana meditators was different from that of control groups. Vipassana meditators showe...

Top-down modeling of hierarchical biological clock mechanisms

Sleep and Biological Rhythms — Wed, 25 Nov 2009 00:00:00 +0100

The behavior of human circadian rhythms could be interpreted within the two-oscillator regime: one for the circadian pacemaker driving temperature/plasma melatonin rhythm and the other for the sleep[ndash]wake rhythm, tentatively called the SCN (suprachiasmatic nucleus) oscillator and non-SCN oscillator, respectively. Recently, the existence of the non-SCN oscillator was demonstrated through showing the possibility of non-photic entrainments by the shifted sleep schedule, and its interactions with the SCN oscillator were disclosed through analyzing the re-entrainment processes. Based on these experimental results at the behavioral level, we developed a phase oscillator model consisting of mutually coupled SCN and non-SCN oscillators, and an extra-oscillator representing an overt sleep[ndas...

Role of PPARα in control of torpor through FGF21–NPY pathway: From circadian clock genes to seasonal change and cardiovascular disease

Sleep and Biological Rhythms — Wed, 04 Nov 2009 00:00:00 +0100

In nature, hibernating animals experience fasting, cold temperature, and short day seasonally. Torpor is a state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of metabolism to adapt to such a severe environment. Ablation of the central clock synchronizer, the suprachiasmatic nucleus in brain, abolishes torpor, a hibernation-like state, implicating the circadian clock involved in this seasonal change. Biologists know well that the energy source of daily heterotherms/hibernators change from glucose to lipids in winter. Here we review several lines of evidence of a master transcriptional regulator in lipid catabolism, peroxisome proliferator-activated receptor [alpha] (PPAR[alpha]), in the control of torpor through the fibroblas...

Restricted feeding-induced entrainment of activity rhythm and peripheral clock rhythm

Sleep and Biological Rhythms — Wed, 04 Nov 2009 00:00:00 +0100

Daily restricted feeding entrains the circadian rhythm of mouse clock gene expression in the central nervous system excluding the suprachiasmatic nucleus, as well as in the peripheral tissues such as the liver, lungs, and heart. In addition to entrainment of the clock gene, daily restricted feeding induces a locomotor activity increase 2[ndash]3 h before the restricted feeding time. The increase of activity is called the food anticipatory activity (FAA). At present, the mechanisms for restricted feeding-induced entrainment are still unknown. In this review, we describe the role of the central nervous system and peripheral tissues in FAA performance and also in entrainment of clock gene expression. (Source: Sleep and Biological Rhythms)

Impact of age on human non-visual responses to light

Sleep and Biological Rhythms — Wed, 04 Nov 2009 00:00:00 +0100

Ageing is associated with increased disturbances in the timing, duration, and quality of sleep. These disruptions may reflect changes in the circadian timing system and/or the sleep homeostat which are both necessary to produce consolidated sleep at an appropriate time. In addition, it is possible that age-related alterations in the detection and transmission of the photic signal responsible for synchronizing the circadian clock may play a role. Ageing is accompanied by many changes within the eye including alterations in pupil size, lens transmission, and number of photoreceptors. The observed increase in ocular lens density with age will diminish the transmission of short wavelength blue light to which the circadian system has been shown to be most sensitive, and may contribute, in part,...

Molecular mechanisms of circadian timekeeping in Drosophila

Sleep and Biological Rhythms — Wed, 30 Sep 2009 23:00:00 +0100

Molecular and genetic studies in the fruit fly Drosophila melanogaster have revealed that the circadian timekeeping mechanism is based on feedback loops in gene expression. These feedback loops, which are highly conserved in mammals, can be divided into temporally distinct transcriptional activation, repression, and reactivation phases. Determining how different phases of the transcriptional feedback cycle are controlled and integrated is necessary to understand the molecular basis of circadian timekeeping. In Drosophila, feedback loop function is initiated when hypophosphorylated CLOCK (CLK) forms a heterodimer with CYCLE (CYC) and binds E-boxes to activate transcription of clock genes including period (per), timeless (tim), vrille (vri), PAR domain protein 1[epsilon] (Pdp1[epsilon]), and...

CIPC-dependent phosphorylation of CLOCK and NPAS2 in circadian clockwork

Sleep and Biological Rhythms — Tue, 29 Sep 2009 23:00:00 +0100

Circadian rhythms are generated by the cell-autonomous circadian clock, in which the clock genes form a transcription/translation-based negative feedback loop. Basic helix-loop-helix (bHLH)-PAS (Period-Arylhydrocarbon receptor nuclear translocator-Single minded) transcription factors, CLOCK and BMAL1, form a complex and bind to E-box elements for activation of the transcription, which is suppressed by circadian binding with a variety of negative regulators. We found that CLOCK protein is mostly kept in the phosphorylated form over the day and is hyperphosphorylated in the suppression phase of E-box-dependent transcription. Ser38, Ser42, and Ser427 were identified as in vivo phosphorylation sites of CLOCK isolated from the mouse liver nuclei, and mutation analysis of the sites revealed that...

Symposia

Sleep and Biological Rhythms — Wed, 23 Sep 2009 16:50:39 +0100

(Source: Sleep and Biological Rhythms)

RNA interference is a powerful tool for chronobiological study in the cricket

Sleep and Biological Rhythms — Thu, 10 Sep 2009 23:00:00 +0100

Circadian rhythms are periodic phenomena recurring with a period of about 24 h that are observed in a variety of physiological functions. The rhythms are driven by an endogenous timing system involving the circadian clock. While recent molecular studies promoted understanding the oscillatory mechanism of the clock in model organisms such as Drosophila, its applicability to other insects still remains to be examined. RNA interference (RNAi) becomes a powerful method to dissect the clock and clock-related mechanisms in non-model insects. Crickets are particularly suitable for the application of RNAi, because a single injection of a clock gene dsRNA has long-lasting effects both on mRNA and behavioral rhythms. In this review, we introduce our current approach to the circadian clock as well as...

Circadian regulation of olfaction and olfactory learning in the cockroach Leucophaea maderae

Sleep and Biological Rhythms — Thu, 10 Sep 2009 23:00:00 +0100

Olfaction is a dominant sensory cue in both vertebrates and invertebrates and, particularly in insects, it often provides critical information utilized in a variety of well-studied behaviors including reproduction, feeding, host-identification, and intra-specific competition. Here I review recent studies on circadian regulation of olfactory receptors and olfactory behaviors in the cockroach Leucophaea maderae. Cockroaches exhibit a robust circadian rhythm in the olfactory response of the antenna, measured by electroantennogram or single-sensillum recording, to both food-related odors and sex pheromone components. Interestingly, peak olfactory sensitivity occurs in the early subjective day, a time when the animals are inactive. These data raise the question of what impact the rhythms in olf...

Author Index

Sleep and Biological Rhythms — Tue, 08 Sep 2009 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Poster presentations

Sleep and Biological Rhythms — Tue, 08 Sep 2009 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Oral presentations

Sleep and Biological Rhythms — Tue, 08 Sep 2009 23:00:00 +0100

(Source: Sleep and Biological Rhythms)

Hastatoside and verbenalin are sleep-promoting components in Verbena officinalis

Sleep and Biological Rhythms — Mon, 17 Aug 2009 23:00:00 +0100

In this study, we examined the sleep-promoting activity of hastatoside, verbenalin, and verbascoside, which are the major iridoids (hastatoside and verbenalin) and polyphenol (verbascoside) components responsible for the pharmacological activity of V. officinalis, by electroencephalographic analysis of rats after oral administration of the compounds. Hastatoside (0.64 mmol/kg of body weight) and verbenalin (1.28 mmol/kg of body weight) increased the total time of non-rapid eye movement sleep during a 9-h period from 23.00 to 08.00 hours by 81% and 42%, respectively, with a lag time of about 3[ndash]5 h after the administration at 20.00 hours (lights-off time). Both compounds also increased the delta activity during non-rapid eye movement sleep. However, verbascoside had no effect on the am...

Epidemiological study of nightmare and sleep paralysis among Japanese adolescents

Sleep and Biological Rhythms — Mon, 03 Aug 2009 23:00:00 +0100

In this study, we have elucidated the prevalence of and factors associated with nightmares and sleep paralysis in Japanese adolescents. We conducted a survey of first-year senior high school students by employing self-administered questionnaires about nightmare and sleep paralysis. All the subjects were first-year students (1164) from three private high schools. The responses of the remaining 916 subjects (568 boys and 348 girls) were considered valid. We found that in Japanese adolescents, the current prevalence of nightmares is 27.4%, and that of sleep paralysis is 7.2%. The lifetime prevalence of sleep paralysis is 30.4%. Results of the multiple logistic regression analysis revealed factors associated with nightmare and sleep paralysis. With regard to nightmares, the adjusted odds ratio...

Efficacy study of a vest-type device for positional therapy in position dependent snorers

Sleep and Biological Rhythms — Sun, 02 Aug 2009 23:00:00 +0100

In conclusion, positional therapy using the recently developed vest-type device is effective at decreasing snoring without subjective and objective adverse effects in position-dependent snorers with or without mild obstructive sleep apnea. (Source: Sleep and Biological Rhythms)

Efficacy and safety of temperature data loggers in measuring compliance with the use of oral appliances

Sleep and Biological Rhythms — Sun, 02 Aug 2009 23:00:00 +0100

The purpose of this study was to verify the cytotoxicity of a temperature data logger (Thermochron iButton, DS1921G; Maxim, Dallas, TX, USA) and to show the clinical use of such loggers in measuring compliance with oral appliances (OA). In the first experimental study (in vitro cytotoxicity test), we used Testskin (Toyobo, Osaka, Japan) to examine the influence on cytotoxicity caused by use of a temperature data logger (Thermochron) in a human dermal tissue model. The cytotoxicity of extracted fluid in which Thermochron was immersed was calculated and only minimal cytotoxic effects were observed. In the second study, six patients with obstructive sleep apnea-hypopnea syndrome were studied to determine compliance with OA use. Thermochron was attached to the surface of the appliance on the b...

Excessive daytime sleepiness in obstructive sleep apnea patients after home CPAP treatment: A long-term outcome study

Sleep and Biological Rhythms — Sun, 02 Aug 2009 23:00:00 +0100

Previous studies have been inconclusive about the improvement in excessive daytime sleepiness (EDS) after continuous positive airway pressure (CPAP) treatment. One hundred and thirty-one obstructive sleep apnea patients, who were on regular home CPAP treatment, were investigated with an overnight polysomnography and daytime multiple sleep latency test (MSLT). Their Epworth Sleepiness Scale (ESS) scores and mean sleep latencies (MSL) before and after treatment were compared. With a mean duration of CPAP treatment for 3.4 ± 2.4 years, improvement in both ESS (12.8 to 9.95) and MSLT (7.32 to 8.92 min) were found (P < 0.001). Residual EDS was found in 38.5% (20 out of 52) and 66.2% (51 out of 77) of subjects, measured by ESS ([ge]14) and MSL ([le]8 min), respectively. Higher body mass index w...

Effects of habitual self-awakening on nocturnal sleep, autonomic activity prior to awakening, and subjective condition after awakening

Sleep and Biological Rhythms — Sat, 23 May 2009 04:00:00 +0100

Some people habitually wake up at a certain time every morning, in the absence of an external signal. People who are engaged in this "habitual self-awakening" reportedly feel better upon awakening and are subsequently less sleepy during the daytime. The present study examined the effects of habitual self-awakening on sleep structure and autonomic nervous system activity before awakening, and on mood after awakening. Data were analyzed from 11 university students who successfully awoke within 30 min of the target time in the self-awakening condition. These same students also participated in a forced-awakening condition. All-night sleep structure for the successful self-awakening night was not different from that observed on the forced-awakening night. However, sleep efficiency decreased, an...

A retrospective analysis of 4000 patients with obstructive sleep apnea in Okinawa, Japan

Sleep and Biological Rhythms — Sun, 10 May 2009 04:00:00 +0100

The causes and risks of death, and role of severity of obstructive sleep apnea (OSA), obesity, and pulmonary function (PF) in OSA patients treated with or without continuous positive airway pressure (CPAP) have been questioned. Using the Okinawa Nakamura Sleep (ONSLEEP) registry, we studied 4000 patients with an obstructive apnea-hypopnea index (AHI) of >5 events/h. Kaplan[ndash]Meier analysis determined survival rates based on use of CPAP therapy and OSA severity. Multivariate Cox proportional hazard analysis determined effects of AHI, body mass index (BMI), PF, and use of CPAP. A total of 135 deaths (3.4%) were registered at the end of follow-up period (62.0 ± 43.4 months, mortality rate 8 per 1000 patient-years). Main causes of death were cardiovascular diseases. Multivariate predictor...

Effects of red ginseng extract on sleep architecture and electroencephalogram power spectra in rats

Sleep and Biological Rhythms — Thu, 07 May 2009 04:00:00 +0100

We evaluated the ability of the ethanol extract of red ginseng (RGE) to regulate sleep architecture. Adult rats were chronically fitted with sleep[ndash]wake recording electrodes. Following post-surgical recovery, rats were habituated extensively to freely moving polygraphic recording conditions. Polygraphic signs of undisturbed sleep[ndash]wake activities were recorded for 12 h after RGE administration. Ginseng treatment produced more time in non-rapid eye movement (NREM) sleep and total sleep. The total percentage of wakefulness decreased comparably, and the number of sleep[ndash]wake cycles was reduced after 10 and 50 mg/kg RGE. RGE (10 mg/kg) administration decreased the power density of cortical electroencephalogram (EEG) [delta]-waves (0.75[ndash]4.5 Hz) and increased [alpha]-waves (...

Sleep patterns and sleep problems among Egyptian school children living in urban, suburban, and rural areas

Sleep and Biological Rhythms — Tue, 05 May 2009 04:00:00 +0100

In conclusion, sleep duration was shorter than that reported in previous studies. Sleep problems are fairly common among elementary school children in the Giza governorate, whether in urban, suburban, or rural areas. Paternal level of education has an impact on the prevalence of sleep problems. (Source: Sleep and Biological Rhythms)

Circadian rhythm sleep disorders: An update

Sleep and Biological Rhythms — Tue, 05 May 2009 04:00:00 +0100

The primary symptom of circadian rhythm sleep disorders (CRSDs) is the inability to sleep during the desired sleep time. CRSDs are divided into two broad classes: (i) disorders not related to forced alterations of the sleep[ndash]wake schedule or light[ndash]dark cycle (including advanced sleep phase disorder [ASPD], delayed sleep phase disorder [DSPD], non-entrained type [NET], and irregular sleep[ndash]wake rhythm [ISWR]); and (ii) disorders related to forced alterations of the sleep[ndash]wake schedule or light[ndash]dark cycle (including shift work sleep disorder [SWSD], jet lag disorder [JLD], and CRSDs related to diseases and medications). DSPD and ASPD are the common primary circadian rhythm disorders. We discuss the recent developments in the pathogenesis, diagnosis, and management...

Clinical effects of high oral dose of donepezil for patients with Alzheimer's disease in Japan

Sleep and Biological Rhythms — Wed, 08 Apr 2009 04:00:00 +0100

Donepezil 10 mg/day gained approval in Japan in August 2007 for the treatment of cognitive dysfunction in advanced Alzheimer's disease. We evaluated the efficacy and adverse effects of donepezil when the dose was increased to 10 mg/day in 61 Japanese patients with Alzheimer's disease. Cognitive function was evaluated using the Revised Hasegawa Dementia Scale (HDS-R) and Mini-Mental State Examination (MMSE) on the day before starting, and at 4, 8, and 24 weeks after starting donepezil 10 mg/day. The relationship with apolipoprotein E4 was also investigated. The HDS-R and MMSE scores were not statistically significantly different at any time after starting donepezil 10 mg/day. It can be anticipated that donepezil 10 mg/day will especially inhibit deterioration of cognitive function in advanc...

Absence of anti-aquaporin-4 antibodies in narcolepsy

Sleep and Biological Rhythms — Sat, 04 Apr 2009 04:00:00 +0100

In this study, we screened for anti-AQP4 antibodies in sera from 251 patients with narcolepsy, 34 with other hypersomnias, and 200 healthy controls by using the radioligand binding assay method. A positive result for anti-AQP4 antibodies was found only in one healthy control subject. All the hypersomnia patients were negative for this antibody. Our results indicated that anti-AQP4 antibody is not useful as a diagnostic marker for narcolepsy and other hypersomnias. (Source: Sleep and Biological Rhythms)

Emergence of the circadian sleep–wake rhythm might depend on conception not on birth timing

Sleep and Biological Rhythms — Tue, 17 Mar 2009 04:00:00 +0100

Developmental changes in the sleep[ndash]wake rhythm of preterm infants were compared with those of full-term infants, to clarify the timing of the developmental change of the sleep[ndash]wake rhythm and its dependence on either conception or birth timing. We obtained sleep log data for two preterm infants, and compared these with previous data gathered from 10 full-term infants over a period from 2 weeks after birth to 3 months after their expected delivery dates. Infant sleep logs were analyzed with the autocorrelation method to investigate the development of the circadian rhythm in each infant's sleep patterns during each weekly session. We then classified the patterns of correlograms into three groups using cluster analysis. The first group (pattern A) showed little evidence of any cir...

Announcement

Sleep and Biological Rhythms — Thu, 12 Mar 2009 04:00:00 +0100

(Source: Sleep and Biological Rhythms)

Restless legs syndrome in a 5-year-old boy with low body stores of iron

Sleep and Biological Rhythms — Thu, 12 Mar 2009 04:00:00 +0100

We report the case of a 5-year-old preschooler with RLS, who presented with an uncomfortable sensation in his toes before bedtime and insomnia. Blood tests showed reduced iron stores (serum ferritin, 15.9 ng/mL). The subjective symptoms and a maternal history of RLS were consistent with pediatric RLS. Iron supplement therapy resulted in improvement in the leg sensation and subjective daytime alertness. We recommend detailed evaluation of iron status in preschoolers with suspected RLS. (Source: Sleep and Biological Rhythms)

Evaluation of the usefulness of the SleepStrip for screening obstructive sleep apnea-hypopnea syndrome in Japan

Sleep and Biological Rhythms — Sun, 08 Mar 2009 05:00:00 +0100

In order to assess the usefulness of the SleepStrip (SS) in screening for obstructive sleep apnea-hypopnea syndrome (OSAHS) in Japanese settings, we measured its sensitivity and specificity against the reference standard diagnostic full-night polysomnography (FN-PSG) using a real-life timeline, and compared them to that of the simultaneously applied pulse oximeter (PO), a routinely used OSAHS screener in Japan. A total of 110 consecutive subjects with the symptoms of OSAHS underwent simultaneous SS and PO screening tests followed by a diagnostic FN-PSG within 7 weeks, a common time frame for accessing PSG in Japan. Data for 83 subjects were available for the final analysis. We analyzed both SS and PO output data as a standalone screening parameter, without combining it with other predictor...

The effects of a 30-min nap during night shift following a prophylactic sleep in the afternoon

Sleep and Biological Rhythms — Tue, 17 Feb 2009 05:00:00 +0100

The purpose of this study was to investigate the effects of a 30-min nap, during a simulated night shift environment, when a prophylactic daytime sleep was implemented prior to the night shift. A repeated-measures counterbalanced design was used which included two experimental conditions: a 30-min nap and a no nap control. In both conditions subjects obtained a 2-h sleep in the afternoon from 15.00[ndash]17.00 hours, which was followed by the night-time nap from 02.30[ndash]03.00 hours in a controlled laboratory environment. Post-nap testing was conducted from 03.10 to 07.00 hours. The participants included 22 adults aged from 18[ndash]35 years who were good sleepers and did not regularly nap. Subjective alertness (Stanford Sleepiness Scale, Karolinska Sleepiness Scale, Visual Analog Scale...

Good esthetic results after modified maxillomandibular advancement for obstructive sleep apnea syndrome

Sleep and Biological Rhythms — Thu, 22 Jan 2009 04:10:32 +0100

Recently, obstructive sleep apnea syndrome (OSAS) is commonly treated conservatively, in particular with continuous positive airway pressure and oral appliance. However, these methods provide only symptomatic relief, and compliance is low. On the other hand, various types of surgical treatment for OSAS have been reported, and maxillomandibular advancement (MMA) is one of the best established and most effective surgical therapies available to improve this condition. However, a major disadvantage of this method is that advancement of the maxilla-mandibular component sometimes has undesired esthetic results. We encountered a 36-year-old woman with a gummy smile and mandibular deficiency. Cephalometric analysis before surgery revealed a narrow upper airway, and polysomnography showed an apnea-...

How is autonomic nervous system activity in subjects who are sleepy but are unable to sleep in the daytime?

Sleep and Biological Rhythms — Tue, 20 Jan 2009 04:01:32 +0100

We investigated changes in the activity of the autonomic nervous system (ANS) in the relaxed condition in subjects who felt sleepy, but were unable to sleep. A total of 1021 subjects underwent daytime polysomnography. The sleep latency (SL) and the visual analog scale (VAS) were used to assess "immediate" objective and subjective sleepiness, respectively. The subjects were assigned to an "Alert-Alert" group (VAS [le] 25 mm, SL [ge] 8 min), a "Sleepy-Alert" group (VAS [ge] 75 mm, SL [ge] 8 min), or a "Sleepy-Sleepy" group (VAS [ge] 75 mm, SL [le] 4 min). In order to assess the ANS, the spectral analysis and the geometric method were used. The ANS data collected during the relaxed condition (after lights off, post-LO) was compared to that obtained during the control condition (before lights ...