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    2644 results match your criteria Chronobiology International [Journal]

    1 OF 53

    The role of the daily feeding rhythm in the regulation of the day/night rhythm in triglyceride secretion in rats.
    Chronobiol Int 2018 Feb 15:1-11. Epub 2018 Feb 15.
    a Hypothalamic Integration Mechanisms , Netherlands Institute for Neuroscience , Amsterdam , The Netherlands.
    Plasma triglyceride (TG) levels show a clear daily rhythm, however, thus far it is still unknown whether this rhythm results from a daily rhythm in TG production, TG uptake or both. Previous studies have shown that feeding activity affects plasma TG concentrations, but it is not clear how the daily rhythm in feeding activity affects plasma TG concentrations. In the present study, we measured plasma TG concentrations and TG secretion rates in rats at 6 Zeitgeber times to investigate whether plasma TG concentrations and TG secretion show a daily rhythm. Read More

    The immune system as a chronotoxicity target of the anticancer mTOR inhibitor everolimus.
    Chronobiol Int 2018 Feb 5:1-14. Epub 2018 Feb 5.
    a Department of Pharmacology, Faculty of Pharmacy , Istanbul University , Beyazit-Istanbul , Turkey.
    The circadian timing system controls many biological functions in mammals including xenobiotic metabolism, detoxification, cell proliferation, apoptosis and immune functions. Everolimus is a mammalian target of rapamycin inhibitor, whose immunosuppressant properties are both desired in transplant patients and unwanted in cancer patients, where it is indicated for its antiproliferative efficacy. Here we sought whether everolimus circadian timing would predictably modify its immunosuppressive effects so as to optimize this drug through timing. Read More

    Premature birth and circadian preference in young adulthood: evidence from two birth cohorts.
    Chronobiol Int 2018 Jan 30:1-10. Epub 2018 Jan 30.
    a Department of Public Health Solutions , National Institute for Health and Welfare , Helsinki and Oulu , Finland.
    A preference for eveningness (being a "night owl") and preterm birth (<37 weeks of gestation) are associated with similar adversities, such as elevated blood pressure, impaired glucose regulation, poorer physical fitness, and lower mood. Yet, it remains unclear if and how preterm birth is associated with circadian preference. The aim of this study was to assess this association across the whole gestation range, using both objective and subjective measurements of circadian preference. Read More

    The influences of cholecystectomy on the circadian rhythms of bile acids as well as the enterohepatic transporters and enzymes systems in mice.
    Chronobiol Int 2018 Jan 30:1-18. Epub 2018 Jan 30.
    a Department of Pharmacy , The First Hospital of Lanzhou University , Lanzhou , China.
    Bile acids (BAs), the most important endogenous and signaling molecules regulate the target transporters and enzymes at transcriptional level, participate in a wide variety of processes throughout the entire gastrointestinal tract to orchestrate homeostasis in vivo. BAs and their metabolism and transportation appear to follow the clear circadian rhythms, and they are recently proposed also as the potential chronobiological signals that can affect the molecular clock mechanism. Cholecystectomy are believed to affect the circadian rhythms of BAs and the relevant enterohepatic transporters and enzymes systems and their regulatory signaling pathways, for the reason that the circadian cycle of gallbladder filling and emptying play a pivotal role in controlling the flow of bile into the intestine and the enterohepatic circulation of BAs. Read More

    Decreased daytime light intensity at nonwindow hospital beds: Comparisons with light intensity at window hospital beds and light exposure in nonhospitalized elderly individuals.
    Chronobiol Int 2018 Jan 26:1-5. Epub 2018 Jan 26.
    b Department of Epidemiology , Nara Medical University School of Medicine , Nara , Japan.
    Light is crucial for the synchronization of internal biological rhythms with environmental rhythms. Hospitalization causes a range of unfavorable medical conditions, including delirium, sleep disturbances, depressed mood, and increased fall, especially in elderly people. The hospital room environment contributes significantly to patients' circadian physiology and behavior; however, few studies have evaluated light intensity in hospital settings. Read More

    Bmal1-deficient mouse fibroblast cells do not provide premature cellular senescence in vitro.
    Chronobiol Int 2018 Jan 26:1-9. Epub 2018 Jan 26.
    a Laboratory of Gene Regulation Research, Graduate School of Biological Sciences , Nara Institute of Science and Technology (NAIST) , Ikoma, Nara , Japan.
    Bmal1 is a core circadian clock gene. Bmal1mice show disruption of the clock and premature aging phenotypes with a short lifespan. However, little is known whether disruption of Bmal1 leads to premature aging at cellular level. Read More

    Mechanisms of social synchrony between circadian activity rhythms in cohabiting marmosets.
    Chronobiol Int 2018 Jan 26:1-15. Epub 2018 Jan 26.
    a Laboratório de Cronobiologia, Departamento de Fisiologia , Universidade Federal do Rio Grande do Norte , Natal/RN , Brazil.
    In marmosets, social synchrony between circadian profiles of activity is stronger in animals that cohabit in a family. The activity of three breeding pairs was recorded by actiwatches to investigate the mechanisms involved in the synchrony between the circadian activity profiles during cohabitation in marmoset reproductive pairs. The dyads were submitted to LD 12:12 (21 days) and LL: 1) cohabitation (24 days), 2) removal of the cage mate (20 days), 3) reintroduction of the mate into the cage of the 1situation (30 days) and 4) removal of the cage mate (7 days). Read More

    Seasonal variation of admission severity and outcomes in ischemic stroke - a consecutive hospital-based stroke registry.
    Chronobiol Int 2018 Jan 26:1-8. Epub 2018 Jan 26.
    a Department of Neurology , Nanjing First Hospital, Nanjing Medical University , Nanjing , P.R. China.
    Different morbidities and mortalities of ischemic stroke may occur among seasons. For detecting the seasonal variations of severity after stroke onset and prognosis, we employed a retrospective analysis on a prospective regional hospital-based stroke registry and included a total of 1039 consecutive patients with onset date from January 2014 to December 2015. Patients were divided into four groups according to the onset seasons. Read More

    Changes in growth and sleep across school nights, weekends and a winter holiday period in two Australian schools.
    Chronobiol Int 2018 Jan 26:1-14. Epub 2018 Jan 26.
    a Sleep and Chronobiology Laboratory , University of South Australia, Centre for Sleep Research , Adelaide , Australia.
    Studies suggest that there may be an association between sleep and growth; however, the relationship is not well understood. Changes in biology and external factors such as school schedule heavily impact the sleep of adolescents, during a critical phase for growth. This study assessed the changes in sleep across school days, weekends and school holidays, while also measuring height and weight changes, and self-reported alterations in food intake and physical activity. Read More

    Effects of lunar phases on short-term, explosive physical performance among young trained athletes.
    Chronobiol Int 2018 Jan 25:1-8. Epub 2018 Jan 25.
    d Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital . Doha , Qatar.
    Beliefs that lunar phases affect human physiology started in ancient times. Research has recently revealed that a physical fitness index increased in sedentary students at the new moon (NM) and full moon (FM) compared to other moon phases. However, the effect of lunar cycle (moon illumination and gravitational pull) on physical performance in athletes was not examined. Read More

    Temporal expression of clock genes in central and peripheral tissues of spotted munia under varying light conditions: Evidence for circadian regulation of daily physiology in a non-photoperiodic circannual songbird species.
    Chronobiol Int 2018 Jan 25:1-16. Epub 2018 Jan 25.
    a IndoUS Center for Biological Timing, Department of Zoology , University of Delhi , Delhi , India.
    We investigated if the duration and/or frequency of the light period affect 24-h rhythm of circadian clock genes in central and peripheral tissues of a non-photoperiodic songbird, the spotted munia (Lonchura punctulata), in which a circannual rhythm regulates the reproductive cycle. We monitored activity-rest pattern and measured 24-h mRNA oscillation of core clock (Bmal1, Clock, Per2, Cry1 and Cry2) and clock-controlled (E4bp4, Rorα and Rev-erbα) genes in the hypothalamus, retina, liver and gut of spotted munia subjected to an aberrant light-dark (LD) cycle (3.5L:3. Read More

    Daily cycle in hepatic lipid metabolism in obese mice, Neotomodon alstoni: Sex differences.
    Chronobiol Int 2018 Jan 25:1-15. Epub 2018 Jan 25.
    a Unidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias , Universidad Nacional Autónoma de México , Juriquilla , Qro.
    Disruption of circadian rhythms influences the pathogenesis of obesity, particularly with the basic regulation of food intake and metabolism. A link between metabolism and the circadian clock is the peroxisome proliferator-activated receptors (PPARs). The Neotomodon alstoni mouse, known as the "Mexican volcano mouse," may develop obesity if fed a normo-caloric diet. Read More

    Association of possible sleep bruxism in children with different chronotype profiles and sleep characteristics.
    Chronobiol Int 2018 Jan 24:1-10. Epub 2018 Jan 24.
    a Department of Pediatric dentistry and Orthodontics of Dentistry College of Federal University of Rio de Janeiro , Rio de Janeiro , Brazil.
    Sleep bruxism (SB) in children has been associated with several sleep characteristics, which may alter their sleep pattern. This change affects the internal biological clock and consequently the chronotype profile. The aim of this study was to evaluate the existence of an association between possible SB in children with specific chronotype profiles and sleep characteristics. Read More

    Population level evidence for seasonality of the human microbiome.
    Chronobiol Int 2018 Jan 17:1-5. Epub 2018 Jan 17.
    a Department of Family Medicine , University of Alberta , Edmonton , Canada.
    The objective of this study is to determine whether human body odors undergo seasonal modulation. We utilized google trends search volume from the United States of America from January 1, 2010 to June 24, 2017 for a number of predetermined body odors. Regression modeling of time series data was completed. Read More

    Psychometric properties of the Epworth Sleepiness Scale: A factor analysis and item-response theory approach.
    Chronobiol Int 2018 Jan 17:1-13. Epub 2018 Jan 17.
    b Social, Cognitive and Affective Neuroscience Unit, Department of Basic Psychological Research and Research Methods, Faculty of Psychology , University of Vienna , Vienna , Austria.
    The purpose of this study is to examine the psychometric properties of the Epworth Sleepiness Scale (ESS) in two languages, German and English. Students from a university in Austria (N = 292; 55 males; mean age = 18.71 ± 1. Read More

    Total sleep deprivation does not significantly degrade semantic encoding.
    Chronobiol Int 2018 Jan 17:1-4. Epub 2018 Jan 17.
    a Sleep and Performance Research Center , Washington State University , Spokane , WA , USA.
    Sleep deprivation impairs performance on cognitive tasks, but it is unclear which cognitive processes it degrades. We administered a semantic matching task with variable stimulus onset asynchrony (SOA) and both speeded and self-paced trial blocks. The task was administered at the baseline and 24 hours later after 30. Read More

    Association of habitual dietary intake with morningness-eveningness and rotating shift work in Japanese female nurses.
    Chronobiol Int 2018 Jan 4:1-13. Epub 2018 Jan 4.
    d Educational Physiology Laboratory, Graduate School of Education, The University of Tokyo , Bunkyo-ku , Tokyo , Japan.
    Rotating shift workers are associated with imbalanced dietary intakes. Rotating shift workers and dietary intakes in adults who do not engage in night work have also been shown to be associated with chronotype. However, no studies have examined associations between morningness-eveningness (i. Read More

    Circadian variations in the clinical presentation of headaches among migraineurs: A study using a smartphone headache diary.
    Chronobiol Int 2017 Dec 28:1-9. Epub 2017 Dec 28.
    d Department of Neurology , Kangnam Sacred Heart Hospital, Hallym University College of Medicine , Seoul , Korea.
    Migraines occur within certain time frames. Nevertheless, information regarding circadian variation in the clinical presentation of migraine is limited. We investigated circadian variations in the clinical presentation of migraine using a smartphone headache diary (SHD). Read More

    Circadian PER2 protein oscillations do not persist in cycloheximide-treated mouse embryonic fibroblasts in culture.
    Chronobiol Int 2018 Jan 28;35(1):132-136. Epub 2017 Dec 28.
    a Department of Systems Biology, Graduate School of Pharmaceutical Sciences , Kyoto University , Kyoto , Japan.
    It is not known whether the endogenous mammalian core clock proteins sustain measurable oscillations in cells in culture where de novo translation is pharmacologically inhibited. We studied here the mammalian core clock protein PER2, which undergoes robust circadian oscillations in both abundance and phosphorylation. With a newly developed antibody that enables tracing the endogenous PER2 protein oscillations over circadian cycles with cultured mouse embryonic fibroblast cells, we provide evidence that PER2 does not persist noticeable circadian rhythms when translation is inhibited. Read More

    Morphological, molecular and hormonal adaptations to early morning versus afternoon resistance training.
    Chronobiol Int 2017 Dec 28:1-15. Epub 2017 Dec 28.
    d Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway.
    It has been clearly established that maximal force and power is lower in the morning compared to noon or afternoon hours. This morning neuromuscular deficit can be diminished by regularly training in the morning hours. However, there is limited and contradictory information upon hypertrophic adaptations to time-of-day-specific resistance training. Read More

    Missed medical appointments during shifts to and from daylight saving time.
    Chronobiol Int 2017 Dec 28:1-5. Epub 2017 Dec 28.
    b Department of Psychology , University of York , York , UK.
    Transitions into and out of Daylight Saving Time (DST) can provide insights into how a minor change to a regular sleep-wake cycle can inadvertently affect health. We examined the relationship between DST and missed medical appointments. Using a large dataset, the proportion of missed appointments were examined prior and post spring and autumn clock changes. Read More

    Epidemiology of objectively measured bedtime and chronotype in US adolescents and adults: NHANES 2003-2006.
    Chronobiol Int 2017 Dec 28:1-19. Epub 2017 Dec 28.
    d Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health , Baltimore , Maryland , US.
    Background: We propose a method for estimating the timing of in-bed intervals using objective data in a large representative US sample, and quantify the association between these intervals and age, sex, and day of the week.

    Methods: The study included 11,951 participants 6 years and older from the National Health and Nutrition Examination Survey (NHANES) 2003-2006, who wore accelerometers to measure physical activity for seven consecutive days. Participants were instructed to remove the device just before the nighttime sleep period and put it back on immediately after. Read More

    Impact of heart-specific disruption of the circadian clock on systemic glucose metabolism in mice.
    Chronobiol Int 2017 Dec 22:1-12. Epub 2017 Dec 22.
    a Department of Physiology , Wakayama Medical University , Wakayama , Japan.
    The daily rhythm of glucose metabolism is governed by the circadian clock, which consists of cell-autonomous clock machineries residing in nearly every tissue in the body. Disruption of these clock machineries either environmentally or genetically induces the dysregulation of glucose metabolism. Although the roles of clock machineries in the regulation of glucose metabolism have been uncovered in major metabolic tissues, such as the pancreas, liver, and skeletal muscle, it remains unknown whether clock function in non-major metabolic tissues also affects systemic glucose metabolism. Read More

    How have our clocks evolved? Adaptive and demographic history of the out-of-African dispersal told by polymorphic loci in circadian genes.
    Chronobiol Int 2017 Dec 20:1-22. Epub 2017 Dec 20.
    c Department of Nervous Diseases , Institute of Professional Education, I.M. Sechenov 1-st Moscow State Medical University , Moscow , Russia.
    The mechanism of the molecular circadian clocks is currently understood as a transcription/translation feedback loop involving more than ten genes. Genetic variation at some of loci in these genes has been shaped by adaptation to environmental factors. In particular, latitudinal clines in allele frequency were documented in several animal species, but the contradictory conclusions were drawn from the results of rare human studies. Read More

    Morning bright light exposure has no influence on self-chosen exercise intensity and mood in overweight individuals - A randomized controlled trial.
    Chronobiol Int 2017 Dec 20:1-9. Epub 2017 Dec 20.
    a Division Sports- and Exercise Medicine, Department of Sport, Exercise and Health , University of Basel , Basel , Switzerland.
    Overweight is a worldwide increasing public health issue. Physical exercise is a useful countermeasure. Overweight individuals choose rather low exercise intensities, but especially high exercise intensities lead to higher energy expenditure and show beneficial health effects compared to lower exercise intensities. Read More

    Gender differences in sleep habits and quality and daytime sleepiness in elementary and high school teachers.
    Chronobiol Int 2017 Dec 20:1-13. Epub 2017 Dec 20.
    b Laboratório de Cronobiologia, Programa de Pós-graduação em Psicobiologia, Departamento de Fisiologia , Universidade Federal do Rio Grande do Norte , Natal , Brazil.
    The extensive workload of teachers inside and outside the classroom may contribute to sleep problems. Such problems may occur more frequently in women due to the combination of professional demands, domestic tasks, and their relatively greater sleep needs compared to men. The objective of this cross-sectional study was to evaluate the influence of gender on sleep habits and quality, and daytime sleepiness in a sample of 243 teachers (77 men and 166 women) using questionnaires. Read More

    A validation study of Fitbit Charge 2™ compared with polysomnography in adults.
    Chronobiol Int 2017 Dec 13:1-12. Epub 2017 Dec 13.
    a Center for Health Sciences, SRI International , Menlo Park , CA , USA.
    We evaluated the performance of a consumer multi-sensory wristband (Fitbit Charge 2™), against polysomnography (PSG) in measuring sleep/wake state and sleep stage composition in healthy adults. In-lab PSG and Fitbit Charge 2™ data were obtained from a single overnight recording at the SRI Human Sleep Research Laboratory in 44 adults (19-61 years; 26 women; 25 Caucasian). Participants were screened to be free from mental and medical conditions. Read More

    Relevance of chronotype for eating patterns in adolescents.
    Chronobiol Int 2017 Dec 12:1-12. Epub 2017 Dec 12.
    a IEL-Nutritional Epidemiology, DONALD Study , University of Bonn , Dortmund , Germany.
    During adolescence, a shift from morningness to eveningness occurs, yet school continues to start early in the morning. Hence, adolescents are at risk for social jetlag, i.e. Read More

    Rates of insufficiency and deficiency of vitamin D levels in elite professional male and female skiers: A chronobiologic approach.
    Chronobiol Int 2017 Dec 12:1-9. Epub 2017 Dec 12.
    b Laboratory of Experimental Biochemistry & Molecular Biology , IRCCS Istituto Ortopedico Galeazzi , Milano , Italia.
    Vitamin D is essential for the maintenance and promotion of musculoskeletal health, for the functioning of the immune, cardiovascular and reproductive systems, and its main action is to keep calcium and phosphate plasmatic physiological concentrations at intestinal, renal and bony level. Vitamin D affects several parameters related to physical performance too and a particularly high percentage of vitamin D insufficiency and deficiency in professional athletes has been observed. Several variables are able to impair the synthesis of 25(OH)D in athletes, specifically both genetic and environmental factors, but the most probable explanation for the deficient/insufficient vitamin D levels is the insufficient ultraviolet B light (UVB) exposure during winter. Read More

    Individual differences in chronotypes associated with academic performance among Chilean University students.
    Chronobiol Int 2017 Dec 12:1-6. Epub 2017 Dec 12.
    d Escuela de nutrición y dietética , Universidad San Sebastian , Concepcion , Chile.
    A chronotype is an individual trait that determines circadian rhythm (dark/light cycle) characteristics, associated with bedtime, waking, and other daily activities. A chronotype is classified as morning, intermediate, and evening. The objective is to associate chronotypes with academic performance in university students. Read More

    Persistence of social jetlag and sleep disruption in healthy young adults.
    Chronobiol Int 2017 Dec 12:1-17. Epub 2017 Dec 12.
    a Department of Epidemiology and Biostatistics , University of South Carolina , Columbia , SC , USA.
    Sleep disruption has been associated with increased risks for several major chronic diseases that develop over decades. Differences in sleep/wake timing between work and free days can result in the development of social jetlag (SJL), a chronic misalignment between a person's preferred sleep/wake schedule and sleep/wake timing imposed by his/her work schedule. Only a few studies have examined the persistence of SJL or sleep disruption over time. Read More

    Eveningness is associated with skipping breakfast and poor nutritional intake in Brazilian undergraduate students.
    Chronobiol Int 2017 Dec 8:1-10. Epub 2017 Dec 8.
    a Post-Graduate Program in Health Sciences, Faculty of Medicine , Federal University of Uberlândia , Uberlândia , Brazil.
    Some studies have proposed that self-reported eveningness, which reflects the preference of performing activities in the evening, may harm nutritional health and influence the eating behavior and nutritional status of individuals. However, the relationship between these variables (eveningness and nutritional status) and the consumption of breakfast, which is currently considered a marker of health, has been insufficiently explored by studies. The aim of this study was to investigate, in undergraduate students, the association between diurnal preference, being overweight, and food consumption (with special focus on breakfast). Read More

    Usual normalization strategies for gene expression studies impair the detection and analysis of circadian patterns.
    Chronobiol Int 2017 Dec 8:1-14. Epub 2017 Dec 8.
    a Laboratory of Molecular Chronobiology , Federal University of Alagoas (UFAL) , Arapiraca , Alagoas , Brazil.
    Recent studies have shown that transcriptomes from different tissues present circadian oscillations. Therefore, the endogenous variation of total RNA should be considered as a potential bias in circadian studies of gene expression. However, normalization strategies generally include the equalization of total RNA concentration between samples prior to cDNA synthesis. Read More

    A randomized phase II trial of induction chemotherapy followed by cisplatin chronotherapy versus constant rate delivery combined with radiotherapy.
    Chronobiol Int 2018 Feb 7;35(2):240-248. Epub 2017 Dec 7.
    b Department of Head and Neck Oncology , Affiliated Hospital of Guizhou Medical University , Guiyang , P. R. China.
    Chronotherapy is no longer a novel concept in cancer treatment after approximately 20 years of development. Many clinical trials have provided strong supporting evidence that chronomodulated treatment yields better results than a traditional dosage regimen. This study aimed to evaluate the adverse reactions, effect on immune functions, and therapeutic efficacy of chronomodulated infusion versus flat intermittent infusion of cisplatin (DDP) combined with intensity-modulated radiation therapy (IMRT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC). Read More

    Effects of genetic variants of ST8SIA2 and NCAM1 genes on seasonal mood changes and circadian preference in the general population.
    Chronobiol Int 2017 Dec 7:1-11. Epub 2017 Dec 7.
    a Department of Psychiatry , Sungkyunkwan University School of Medicine, Samsung Medical Center , Seoul , Korea.
    ST8SIA2 and NCAM1 are functionally related genes forming polysialic acid (PSA) - neural cell adhesion molecule (NCAM) complex in suprachiasmatic nucleus (SCN), the regulating site of circadian biological rhythm. In this study, the relationship of ST8SIA2 and NCAM1 with circadian and seasonal rhythms of human behavior was explored. Subjects were 261 healthy Korean adults who were free of any history of clinically significant psychiatric symptoms. Read More

    Perspectives on the relevance of the circadian time structure to workplace threshold limit values and employee biological monitoring.
    Chronobiol Int 2017 7;34(10):1439-1464. Epub 2017 Dec 7.
    c American Association for Medical Chronobiology and Chronotherapeutics , Roseville , MN , USA.
    The circadian time structure (CTS) and its disruption by rotating and nightshift schedules relative to work performance, accident risk, and health/wellbeing have long been areas of occupational medicine research. Yet, there has been little exploration of the relevance of the CTS to setting short-term, time-weighted, and ceiling threshold limit values (TLVs); conducting employee biological monitoring (BM); and establishing normative reference biological exposure indices (BEIs). Numerous publications during the past six decades document the CTS substantially affects the disposition - absorption, distribution, metabolism, and elimination - and effects of medications. Read More

    Forced desynchronization model for a diurnal primate.
    Chronobiol Int 2018 Jan 6;35(1):35-48. Epub 2017 Dec 6.
    a Laboratório de Neurobiologia e Ritmicidade Biológica, Departamento de Fisiologia , Universidade Federal do Rio Grande do Norte , Natal , Rio Grande do Norte , Brazil.
    The circadian system is organized in a hierarchy of multiple oscillators, with the suprachiasmatic nucleus (SCN) as the master oscillator in mammals. The SCN is formed by a group of coupled cell oscillators. Knowledge of this coupling mechanism is essential to understanding entrainment and the expression of circadian rhythms. Read More

    Association of shiftwork and leukocytes among national health and nutrition examination survey respondents.
    Chronobiol Int 2017 Dec 6:1-5. Epub 2017 Dec 6.
    a Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC.
    Shift workers may experience disrupted sleep-wake or circadian cycles which, in turn, may lead to major health problems such as hypertension, obesity, and diabetes. Research indicates that shift workers have increased levels of leukocytes. Data from the National Health and Nutrition Examination Survey (2005-2010) examined the relationship between self-reported current shiftwork and leukocytes with adjustment for important confounders. Read More

    Features of the daily rhythms of blood melatonin and glucose in goats during different natural photoperiod.
    Chronobiol Int 2017 Nov 28:1-7. Epub 2017 Nov 28.
    b Department of Veterinary Science , University of Messina, Polo Universitario dell'Annunziata , Messina , Italy.
    The scope of the present study was to explore the features of the daily rhythms of plasma melatonin and blood glucose in goats during different natural photoperiod imposed by the four seasons. Five Sarda breed pluriparus female goats, 2 years old, with a mean body weight 40.5 ± 2. Read More

    Decrease in scale invariance of activity fluctuations with aging and in patients with suprasellar tumors.
    Chronobiol Int 2017 Nov 28:1-10. Epub 2017 Nov 28.
    b Department of Molecular Cell Biology , Laboratory for Neurophysiology, Leiden University Medical Center , Leiden , The Netherlands.
    Motor activity in healthy young humans displays intrinsic fluctuations that are scale-invariant over a wide range of time scales (from minutes to hours). Human postmortem and animal lesion studies showed that the intact function of the suprachiasmatic nucleus (SCN) is required to maintain such scale-invariant patterns. We therefore hypothesized that scale invariance is degraded in patients treated for suprasellar tumors that compress the SCN. Read More

    Prognostic significance of downregulated BMAL1 and upregulated Ki-67 proteins in nasopharyngeal carcinoma.
    Chronobiol Int 2017 Nov 27:1-10. Epub 2017 Nov 27.
    c Guizhou Medical University , Guiyang , PR China.
    This study assessed the prognostic value of BMAL1 and Ki-67 expression in patients with nasopharyngeal carcinoma. Level of BMAL1 mRNA was assessed in tissue specimens from 36 nasopharyngeal carcinomas and 20 nasopharyngeal chronic inflammations using quantitative reverse transcriptase-polymerase chain reaction. Expression of BMAL1 and Ki-67 proteins was analyzed immunohistochemically in 90 paired nasopharyngeal carcinoma and distant normal tissues. Read More

    The choroid plexus harbors a circadian oscillator modulated by estrogens.
    Chronobiol Int 2018 Feb 27;35(2):270-279. Epub 2017 Nov 27.
    a CICS-UBI - Health Sciences Research Centre , University of Beira Interior , Covilhã , Portugal.
    The suprachiasmatic nucleus (SCN) of the hypothalamus is considered the master circadian oscillator in mammals. However, extra-SCN structures in the brain also display daily rhythms. Recently, we have demonstrated that the choroid plexus (CP) expresses core clock genes that are subjected to circadian regulation in a sex-dependent manner. Read More

    Relationship between shift work schedule and self-reported sleep quality in Chinese employees.
    Chronobiol Int 2018 Feb 27;35(2):261-269. Epub 2017 Nov 27.
    a Department of Toxicology, School of Public Health , Guangxi Medical University , Nanning , China.
    Few studies have reported on the effects of fixed and rotating shift systems on the prevalence of sleep disturbance. Thus, in this study, the relationships between different work schedules and sleep disturbance in Chinese workers were investigated. A total of 2180 workers aged 19-65 years responded to the self-report questionnaire on shift work schedule (fixed day-shift, fixed night-shift, two-shift or three-shift system), working hours a day, and working days a week, physical effort, subjective sleep quality and subjective mental state. Read More

    Diurnal variation and reliability of the urine lactate concentration after maximal exercise.
    Chronobiol Int 2018 Jan 27;35(1):24-34. Epub 2017 Nov 27.
    a School of Physical Education and Sport Science , Aristotle University of Thessaloniki , Thessaloniki , Greece.
    The postexercise urine lactate concentration is a novel valid exercise biomarker, which has exhibited satisfactory reliability in the morning hours under controlled water intake. The aim of the present study was to investigate the diurnal variation of the postexercise urine lactate concentration and its reliability in the afternoon hours. Thirty-two healthy children (11 boys and 21 girls) and 23 adults (13 men and 10 women) participated in the study. Read More

    Shift work and sleep disorder comorbidity tend to go hand in hand.
    Chronobiol Int 2018 Feb 20;35(2):219-228. Epub 2017 Nov 20.
    a Department of Psychology , University of Amsterdam , Amsterdam, The Netherlands.
    Taking into consideration that shift work has a wide-ranging impact on circadian and sleep functioning, it seems likely that shift work increases the risk of a general sleep disturbance, spread out over a multitude of comorbid sleep disorders. The aim of the present study is to analyze and present the sleep disorder data of 250 shift workers and 971 permanent day workers, taken from a nationally representative sample. Additional data concerning duration, timing, and quality of sleep, daytime functioning and social/family variables were added to the analyses. Read More

    Chronotype description: In search of a solid subjective amplitude scale.
    Chronobiol Int 2017 20;34(10):1388-1400. Epub 2017 Nov 20.
    b Vrije Universiteit Brussel, Faculty of Psychology and Educational Sciences , Department of Experimental and Applied Psychology , Brussels , Belgium.
    The term "subjective circadian amplitude" refers to the range or the distinctness of diurnal variations of arousal, that is, the awareness (or lack thereof) of difference between hyper- and hypo-activation phases, the ability to volitionally modulate one's own psychophysiological state, the strength of morning-evening preferences and flexibility of the rhythm or perceived stability of the circadian phase. The complexity of this construct is the source of difficulties in research and measurement. The psychometric features of distinctness subscales of the Chronotype Questionnaire and the Caen Chronotype Questionnaire are not satisfactory. Read More

    Effects of circadian clock protein Per1b on zebrafish visual functions.
    Chronobiol Int 2018 Feb 20;35(2):160-168. Epub 2017 Nov 20.
    a Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences , University of Science and Technology of China , Hefei , Anhui Province , P. R. China.
    The circadian clock is an endogenous and entrainable time-keeping mechanism with a period of approximately 24 h, operated by transcription/translation feedback loops composed of circadian clock genes and their proteins. The visual system displays robust circadian changes. Relatively little, however, is known about the mechanisms underlying visual circadian rhythmicity. Read More

    Circadian phase, circadian period and chronotype are reproducible over months.
    Chronobiol Int 2018 Feb 17;35(2):280-288. Epub 2017 Nov 17.
    c Biological Rhythms Research Lab , Rush University Medical Center , Chicago , IL 60612 , USA.
    The timing of the circadian clock, circadian period and chronotype varies among individuals. To date, not much is known about how these parameters vary over time in an individual. We performed an analysis of the following five common circadian clock and chronotype measures: 1) the dim light melatonin onset (DLMO, a measure of circadian phase), 2) phase angle of entrainment (the phase the circadian clock assumes within the 24-h day, measured here as the interval between DLMO and bedtime/dark onset), 3) free-running circadian period (tau) from an ultradian forced desynchrony protocol (tau influences circadian phase and phase angle of entrainment), 4) mid-sleep on work-free days (MSF from the Munich ChronoType Questionnaire; MCTQ) and 5) the score from the Morningness-Eveningness Questionnaire (MEQ). Read More

    Rest-activity circadian rhythm and sleep quality in patients with binge eating disorder.
    Chronobiol Int 2018 Feb 16;35(2):198-207. Epub 2017 Nov 16.
    a Department of Biomedical Sciences for Health , University of Milan , Milan , Italy.
    Recent findings suggest that altered rest-activity circadian rhythms (RARs) are associated with a compromised health status. RARs abnormalities have been observed also in several pathological conditions, such as cardiovascular, neurological, and cancer diseases. Binge eating disorder (BED) is the most common eating disorder, with a prevalence of 3. Read More

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