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Chronobiology International

Maureen Friedrichs, Isa Kolbe, Julia Seemann, Anthony H Tsang, Lisa Cherradi, Johannes Klein, Henrik Oster
Circadian clock-controlled 24-h oscillations in adipose tissues play an important role in the regulation of energy homeostasis, thus representing a potential drug target for prevention and therapy of metabolic diseases. For pharmacological screens, scalable adipose model systems are needed that largely recapitulate clock properties observed in vivo. In this study, we compared molecular circadian clock regulation in different ex vivo and in vitro models derived from murine adipose tissues. Explant cultures from three different adipose depots of PER2::LUC circadian reporter mice revealed stable and comparable rhythms of luminescence ex vivo...
July 11, 2018: Chronobiology International
Wen-Pei Chang
When shift nurses change shifts, it is likely to affect the cortisol patterns of their bodies and sleep quality. The objectives of this study was to verify the influence of monthly rotating day, evening and night shifts on the sleep quality of female nurses and determine whether the cortisol awakening response (CAR) mediates this relationship. A total of 132 female shift nurses were recruited, and ultimately 128 complete questionnaires and samples were obtained (subject loss rate = 3.0%) from 45 day-shift nurses, 44 evening-shift nurses and 39 night-shift nurses at a teaching hospital in Northern Taiwan...
July 11, 2018: Chronobiology International
Jiayue Ding, Zhuoxuan Bai, Da Zhou, Xiangyu Li, Gary Benjamin Rajah, Yuchuan Ding, Jie Han, Xunming Ji, Ran Meng
Circadian rhythms can affect physical or mental activities as well as the time of stroke onset. The impact of circadian rhythms on acute ischemic stroke (AIS) patients treated by recombinant alteplase (rt-PA) is still incongruent. This study aims to consider whether the outcomes of thrombolysis differ depending on stroke onset time and rt-PA infusion time in patients with AIS. A total of 447 AIS patients, who underwent rt-PA intravenous infusion within 4.5 hours after stroke onset, were enrolled in this study consecutively from June 2010 through December 2016...
July 11, 2018: Chronobiology International
Christopher J Gordon, Maria Comas, Svetlana Postnova, Christopher B Miller, Dibyendu Roy, Delwyn J Bartlett, Ronald R Grunstein
Travel across time zones disrupts circadian rhythms causing increased daytime sleepiness, impaired alertness and sleep disturbance. However, the effect of repeated consecutive transmeridian travel on sleep-wake cycles and circadian dynamics is unknown. The aim of this study was to investigate changes in alertness, sleep-wake schedule and sleepiness and predict circadian and sleep dynamics of an individual undergoing demanding transmeridian travel. A 47-year-old healthy male flew 16 international flights over 12 consecutive days...
July 11, 2018: Chronobiology International
Bohumila Krčmárová, Matúš Krčmár, Marianna Schwarzová, Peter Chlebo, Zuzana Chlebová, Radoslav Židek, Adriana Kolesárová, Katarína Zbyňovská, Eva Kováčiková, Simon Walker
Previous findings suggest that performing strength training (ST) in the evening may provide greater benefit for young individuals. However, this may not be optimal for the older population. The purpose of this study was to compare the effects of a 12-week ST program performed in the morning vs. evening on strength, functional capacity, metabolic biomarker and basal hormone concentrations in older women. Thirty-one healthy older women (66 ± 4 years, 162 ± 4 cm, 75 ± 13 kg) completed the study. Participants trained in the morning (M) (07:30, n = 10), in the evening (E) (18:00, n = 10), or acted as a non-training control group (C) (n = 11)...
July 9, 2018: Chronobiology International
Michail E Keramidas, Christoph Siebenmann, Lena Norrbrand, Magnus Gadefors, Ola Eiken
The purpose of the study was to evaluate the recuperative efficacy of pre-exercise napping on physical capacity after military sustained operations (SUSOPS) with partial sleep deprivation. Before and after a 2-day SUSOPS, 61 cadets completed a battery of questionnaires, and performed a 2-min lunges trial and a 3,000-m running time-trial. After the completion of SUSOPS, subjects were randomized to either a control [without pre-exercise nap (CON); n = 32] or a nap [with a 30-min pre-exercise nap (NAP); n = 29] group...
July 9, 2018: Chronobiology International
D Weinert, K Schöttner, A C Meinecke, J Hauer
The Djungarian hamsters of our breeding colony show unstable daily activity patterns when kept under standard laboratory conditions. Moreover, part of them develops a delayed activity onset (DAO) or an arrhythmic phenotype. In former studies, we have shown that the system of photic entrainment works at its limits. If the period length (tau) increases, which is the case in DAO hamsters, the light-induced phase advances are too small to compensate the daily delay of the activity rhythm caused by tau being longer than 24 h...
July 9, 2018: Chronobiology International
Armiya Sultan, Atanu Kumar Pati, Vivek Choudhary, Arti Parganiha
Chemotherapy administration may result in the disruption of circadian rhythms and impairment of quality of life (QoL) of cancer patients. Nevertheless, we have little knowledge on the long-term consequences of chemotherapy and the effects of hospitalization. In the present study, we employed the two-factor repeated-measure cross-sectional design to determine the effects of chemotherapy and hospitalization on rest-activity (RA) rhythm and QoL of breast cancer patients. Initially, we randomly selected 39 inpatients and 42 outpatients, scheduled to receive six cycles of chemotherapy, from the Regional Cancer Center (RCC), Raipur, India...
July 9, 2018: Chronobiology International
Takafumi Fukuda, Atsushi Haraguchi, Masaki Takahashi, Takashi Nakaoka, Mayuko Fukazawa, Jin Okubo, Mamiho Ozaki, Ayana Kanatome, Rena Ohya, Yutaka Miura, Kuniaki Obara, Shigenobu Shibata
In mammals, daily physiological events are regulated by the circadian rhythm, which comprises two types of internal clocks: the central clock and peripheral clocks. Circadian rhythm plays an important role in maintaining physiological functions including the sleep-wake cycle, body temperature, metabolism and organ functions. Circadian rhythm disorder, which is caused, for example, by an irregular lifestyle or long-haul travel, increases the risk of developing disease; therefore, it is important to properly maintain the rhythm of the circadian clock...
July 3, 2018: Chronobiology International
Kristina Hasakova, Marian Vician, Richard Reis, Michal Zeman, Iveta Herichova
Recent evidence supports the important role of the circadian system in cancer progression in humans. The aim of the present study is to evaluate clock (cry1, cry2 and per2) and clock-controlled (vascular endothelial growth factor-a, early growth response protein 1 and estrogen receptor β) gene expression in colorectal cancer and adjacent tissue and identify a possible link between survival of patients and expression of above mentioned genes. The study includes 64 patients of both sexes with previously diagnosed colorectal cancer...
June 28, 2018: Chronobiology International
Jacopo Antonino Vitale, Giovanni Lombardi, Andi Weydahl, Giuseppe Banfi
Rhythms can be observed at all levels of the biologic integration in humans. The observation that a biological or physiological variable shows a circadian rhythm can be explained by several multifactorial systems including external (exogenous), internal (endogenous) and psychobiological (lifestyle) mechanisms. Our body clock can be synchronized with the environment by external factors, called "synchronizers", i.e. the light-dark cycle, but it is also negatively influenced by some pathological conditions or factors, called "chronodisruptors," i...
June 28, 2018: Chronobiology International
Marissa J Maroni, Kimberly M Capri, Alexis V Cushman, Isabella K Monteiro De Pina, Madison H Chasse, Joseph A Seggio
Disruptions to the circadian rhythm can lead to altered metabolism. Modification of thyroid function may be a reason why circadian misalignment may contribute to future metabolic disorders. We investigated whether circadian disruption through constant light (LL) can lead to variations in hormone levels associated with thyroid function. Mice were exposed to LL or a 12:12 Light:Dark (LD) cycle for 6 weeks; then glucose tolerance and thyroid hormone levels were measured at ZT 6 and ZT 18. There was day/night variation in glucose tolerance, but LL had no effect...
June 28, 2018: Chronobiology International
Qingting Wang, Ying Cui, Purrunsing Yogendranath, Ningning Wang
Hyperphosphatemia is a common complication of chronic kidney disease (CKD) and is associated with cardiovascular disease (CVD), which has contributed to an increase in mortality of CKD patients. The onset of CVD often varies by time-of-day. Acute myocardial infarction or ventricular arrhythmia occurs most frequently during early morning. Blood pressure (BP) and heart rate circadian rhythms account for the diurnal variations in CVD. Preservation of normal circadian time structure from the cardiomyocyte level to the whole organ system is essential for cardiovascular health and CVD prevention...
June 27, 2018: Chronobiology International
Colin M Robertson, Samuel A Pullinger, William R Robinson, Mathew E Smith, Jatin G Burniston, James M Waterhouse, Ben J Edwards
We have investigated the magnitude of diurnal variation in back squat and bench press performance using the MuscleLab force velocity transducer. Thirty resistance-trained males (mean ± SD: age 21.7 ± 1.4 years; body mass 80.5 ± 4.5 kg; height 1.79 ± 0.06 m) underwent two sessions at different times of day: morning (M, 07:30 h) and evening (E, 17:30 h). Each session included a period when rectal temperature (Trec ) was measured at rest, a 5-min standardized 150 W warm-up on a cycle ergometer, then defined programme of bench press (at 20, 40 and 60 kg) and back squat (at 30, 50 and 70 kg) exercises...
June 26, 2018: Chronobiology International
Jungyoon Kim, Boncho Ku, Jang-Han Bae, Gyu-Cheol Han, Jaeuk U Kim
Probing the electrical response of the human body is minimally invasive and a promising area of investigation for future health care. The electrical responses of individuals may vary depending on daily physiological rhythms or environmental changes, which may hamper their prediction for pathological status. In this study, we observed circadian expressions via both alternating current (AC) and direct current (DC) electrical responses of the human body using bioelectrical impedance analysis (BIA) and electrodermal activity (EDA)...
June 25, 2018: Chronobiology International
Julia Maruani, George Anderson, Bruno Etain, Michel Lejoyeux, Frank Bellivier, Pierre A Geoffroy
Bipolar disorders (BDs) are severe and common psychiatric disorders. BD pathogenesis, clinical manifestations and relapses are associated with numerous circadian rhythm abnormalities. In addition, infradian fluctuations of mood, social activity, weight and sleep patterns are very frequent in BD. Disease course with a seasonal pattern (SP) occurs in approximately 25% of depressive and 15% of manic episodes, which is coupled to a more severe disease symptomatology. The pathophysiological mechanisms of seasonal effects in BD await clarification, with likely important clinical consequences...
June 25, 2018: Chronobiology International
Pablo Martin Lopez, Luciana Beatriz Abrahan, Martin Roland Ralph, Verónica Sandra Valentinuzzi
Insects express diverse behavioral rhythms synchronized to environmental cycles. While circadian entrainment to light-dark cycles is ubiquitous in living organisms, synchronization to non-photic cycles may be critical for hematophagous bugs that depend on rhythmic hosts. The purpose was to determine whether Triatoma infestans are capable of synchronizing to the circadian rhythms of potential hosts with temporally distinct activity patterns; and, if so, if this synchronization occurs through masking or entrainment...
June 22, 2018: Chronobiology International
Min Xie, Khyra Sarah Utzinger, Kerstin Blickenstorfer, Brigitte Leeners
Circadian and circannual rhythms influence not only the environment, but also human physiology. In times of increasing numbers of couples struggling with infertility, and thus increasing demand for successful assisted reproduction, the aim of our study was to evaluate circadian and circannual rhythms and their association with semen quality. A total of 12 245 semen samples from 7068 men, collected at the andrology laboratory of the Department of Reproductive Endocrinology, University Hospital Zurich, between 1994 and 2015, were uniformly analysed in terms of sperm concentration, total sperm count, progressive motility and normal morphology...
June 18, 2018: Chronobiology International
Kate Porcheret, Lucien Wald, Lin Fritschi, Menno Gerkema, Marijke Gordijn, Martha Merrrow, Shantha M W Rajaratnam, Daniel Rock, Tracey L Sletten, Guy Warman, Katharina Wulff, Till Roenneberg, Russell G Foster
In humans and most other species, changes in the intensity and duration of light provide a critical set of signals for the synchronisation of the circadian system to the astronomical day. The timing of activity within the 24 h day defines an individual's chronotype, i.e. morning, intermediate or evening type. The aim of this study was to investigate the associations between environmental light exposure, due to geographical location, on the chronotype of university students. Over 6 000 university students from cities in the Northern Hemisphere (Oxford, Munich and Groningen) and Southern Hemisphere (Perth, Melbourne and Auckland) completed the Munich ChronoType Questionnaire...
June 18, 2018: Chronobiology International
Raymond W Matthews, Thomas G Kontou, Anjum Naweed, Charli Sargent, Gregory D Roach
This study investigates the effect of passenger and phone conversations on sleep-restricted driving. Six volunteers (50% male, mean age 24.8 ± 4.3 years) had their sleep restricted to 4 h in bed followed by a 20-min simulated drive on three separate occasions. Each drive included either a passenger conversation, a mobile phone conversation or a quiet passenger. The effect size of a phone conversation on lane deviation was large while passenger conversation was small. The main effect of conversation on lane deviation was non-significant (F(2,10) = 2...
June 12, 2018: Chronobiology International
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