Read by QxMD icon Read

Circadian biology

Joseph F O'Grady, Laura S Hoelters, Martin T Swain, David C Wilcockson
BACKGROUND: Talitrus saltator is an amphipod crustacean that inhabits the supralittoral zone on sandy beaches in the Northeast Atlantic and Mediterranean. T. saltator exhibits endogenous locomotor activity rhythms and time-compensated sun and moon orientation, both of which necessitate at least one chronometric mechanism. Whilst their behaviour is well studied, currently there are no descriptions of the underlying molecular components of a biological clock in this animal, and very few in other crustacean species...
2016: PeerJ
Kevin A McGoff, Xin Guo, Anastasia Deckard, Christina M Kelliher, Adam R Leman, Lauren J Francey, John B Hogenesch, Steven B Haase, John L Harer
We present a novel approach, the Local Edge Machine, for the inference of regulatory interactions directly from time-series gene expression data. We demonstrate its performance, robustness, and scalability on in silico datasets with varying behaviors, sizes, and degrees of complexity. Moreover, we demonstrate its ability to incorporate biological prior information and make informative predictions on a well-characterized in vivo system using data from budding yeast that have been synchronized in the cell cycle...
October 19, 2016: Genome Biology
Casey O Diekman, Amitabha Bose
Circadian oscillators found across a variety of species are subject to periodic external light-dark forcing. Entrainment to light-dark cycles enables the circadian system to align biological functions with appropriate times of day or night. Phase response curves (PRCs) have been used for decades to gain valuable insights into entrainment; however, PRCs may not accurately describe entrainment to photoperiods with substantial amounts of both light and dark due to their reliance on a single limit cycle attractor...
October 17, 2016: Journal of Biological Rhythms
Amandine Chaix, Amir Zarrinpar, Satchidananda Panda
Circadian clocks are cell-autonomous timing mechanisms that organize cell functions in a 24-h periodicity. In mammals, the main circadian oscillator consists of transcription-translation feedback loops composed of transcriptional regulators, enzymes, and scaffolds that generate and sustain daily oscillations of their own transcript and protein levels. The clock components and their targets impart rhythmic functions to many gene products through transcriptional, posttranscriptional, translational, and posttranslational mechanisms...
October 10, 2016: Journal of Cell Biology
Mel S Lee, Tsung-Cheng Yin, Pei-Hsun Sung, John Y Chiang, Cheuk-Kwan Sun, Hon-Kan Yip
Despite state-of-the-art pharmaceutical regimens, continuous improvements in diagnostic techniques as well as refinements in equipment and interventional procedures, many diseases remain refractory to conventional therapies. Recent advances in stem cell (SC) biology have opened an avenue to exploring its therapeutic potential in various disease entities, especially those that are ischemia-related and refractory to conventional treatment. A number of experimental studies and clinical trials have already demonstrated promising outcomes...
October 13, 2016: Journal of Pineal Research
Udaya Seneviratne, Ray C Boston, Mark Cook, Wendyl D'Souza
OBJECTIVE: We sought to investigate the temporal patterns and sleep-wake cycle-related epileptiform discharges (EDs) in genetic generalized epilepsies (GGEs). METHODS: We studied 24-hour ambulatory electroencephalography (EEG) recordings of patients with GGE, diagnosed and classified according to the International League against Epilepsy criteria. We manually coded the type of discharge, time of occurrence, duration, and arousal state of each ED. We employed mixed effects Poisson regression modeling to study the temporal distribution of epileptiform discharges...
October 7, 2016: Epilepsy & Behavior: E&B
Walter Wilczynski, Deborah I Lutterschmidt
A new study shows that nocturnal courtship vocalization is regulated by a circadian rhythm and potentiated by melatonin at multiple timescales. These findings are in contrast to those in diurnal vocalizers and provide a striking example of melatonin's niche-specific functions.
October 10, 2016: Current Biology: CB
M Schönfelder, H Hofmann, T Schulz, T Engl, D Kemper, B Mayr, C Rautenberg, R Oberhoffer, D Thieme
Administration of low amounts of endogenous hormones - so called micro-dosages - are supposed to represent a major challenge in doping analysis. To model such a situation, we have studied transdermal administrations of 2.4 mg/24 h testosterone patches and examined various steroid concentrations in blood, urine and saliva of 11 volunteers. Multiple samples were collected at t = 0, 3, 6, 9, 24, 48 and 72 h in four different phases, i.e. all combinations with/without physical exercise and with/without testosterone...
October 10, 2016: Drug Testing and Analysis
Jing Men, Yongyang Huang, Jitendra Solanki, Xianxu Zeng, Aneesh Alex, Jason Jerwick, Zhan Zhang, Rudolph E Tanzi, Airong Li, Chao Zhou
Optical coherence tomography (OCT) is a promising research tool for brain imaging and developmental biology. Serving as a three-dimensional optical biopsy technique, OCT provides volumetric reconstruction of brain tissues and embryonic structures with micrometer resolution and video rate imaging speed. Functional OCT enables label-free monitoring of hemodynamic and metabolic changes in the brain in vitro and in vivo in animal models. Due to its non-invasiveness nature, OCT enables longitudinal imaging of developing specimens in vivo without potential damage from surgical operation, tissue fixation and processing, and staining with exogenous contrast agents...
July 2016: IEEE Journal of Selected Topics in Quantum Electronics
Raymond van Ee, Sander Van de Cruys, Luc J M Schlangen, Björn N S Vlaskamp
A daily rhythm that is not in synchrony with the environmental light-dark cycle (as in jetlag and shift work) is known to affect mood and health through an as yet unresolved neural mechanism. Here, we combine Bayesian probabilistic 'cue-conflict' theory with known physiology of the biological clock of the brain, entailing the insight that, for a functional pacemaker, it is sufficient to have two interacting units (reflecting environmental and internal time-of-day cues), without the need for an extra homuncular directing unit...
October 5, 2016: Trends in Neurosciences
Andrew Korenevsky, Yulia Milyutina, Ljudmila Kozina, Alexander Arutjunyan
Industrial xenobitics, as well as endogenous damaging factors, such as L-homocysteine, are a well-known source of reactive oxygen species that disrupt biological processes. Among many others, luteinizing hormone releasing hormone synthesis and secretion mediated by a variety of neurotransmitters, which are under control of the hypothalamus and pineal gland, may be put in peril by reactive oxygen species. Their formation can be one of the reasons for the reproductive function shutdown in ageing as the generic response to the damaging factors independent of their nature...
October 6, 2016: Current Aging Science
Thaíse Campos Mondin, Taiane de Azevedo Cardoso, Luciano Dias de Mattos Souza, Karen Jansen, Pedro Vieira da Silva Magalhães, Flávio Kapczinski, Ricardo Azevedo da Silva
BACKGROUND: It is known that sleep disturbance has been considered a trait-marker of mood disorders. However, the role of disruptions in biological rhythms, such as eating, activity, and social patterns, needs to be better understood. AIM: To assess the differences in biological rhythms in subjects with bipolar disorder, major depressive disorder, and healthy controls. We also tested the association between disruptions of biological rhythms and circadian preferences...
September 30, 2016: Journal of Psychiatric Research
Lonnele J Ball, Oxana Palesh, Lance J Kriegsfeld
Most physiological processes in the brain and body exhibit daily (circadian) rhythms coordinated by an endogenous master clock located in the suprachiasmatic nucleus of the hypothalamus that are essential for normal health and functioning. Exposure to sunlight during the day and darkness at night optimally entrains biological rhythms to promote homeostasis and human health. Unfortunately, a major consequence of the modern lifestyle is increased exposure to sun-free environments during the day and artificial lighting at night...
October 2016: Endocrine Reviews
Shu-Feng Zhang, Chun-Juan Yuan, Ying Chen, Xiao-Huang Chen, Dong-Xu Li, Jiu-Ling Liu, Lin Lin, Da-Zhi Wang
Phosphorus (P) is a limiting macronutrient for diatom growth and productivity in the ocean. Much effort has been devoted to the physiological response of marine diatoms to ambient P change, however, the whole-genome molecular mechanisms are poorly understood. Here, we utilized RNA-Seq to compare the global gene expression patterns of a marine diatom Skeletonema costatum grown in inorganic P-replete, P-deficient, and inorganic- and organic-P resupplied conditions. In total 34,942 unique genes were assembled and 20...
2016: Frontiers in Microbiology
Seth D Rhoades, Arjun Sengupta, Aalim M Weljie
Sleep and circadian rhythms studies have recently benefited from metabolomics analyses, uncovering new connections between chronobiology and metabolism. From untargeted mass spectrometry to quantitative nuclear magnetic resonance spectroscopy, a diversity of analytical approaches has been applied for biomarker discovery in the field. In this review we consider advances in the application of metabolomics technologies which have uncovered significant effects of sleep and circadian cycles on several metabolites, namely phosphatidylcholine species, medium-chain carnitines, and aromatic amino acids...
October 1, 2016: Current Opinion in Biotechnology
Julia M Selfridge, Tetsuya Gotoh, Samuel Schiffhauer, JingJing Liu, Philip E Stauffer, Andrew Li, Daniel G S Capelluto, Carla V Finkielstein
Circadian rhythms are a collection of endogenously driven biochemical, physiological, and behavioral processes that oscillate in a 24-h cycle and can be entrained by external cues. Circadian clock molecules are responsible for the expression of regulatory components that modulate, among others, the cell's metabolism and energy consumption. In clinical practice, the regulation of clock mechanisms is relevant to biotransformation of therapeutics. Accordingly, xenobiotic metabolism and detoxification, the two processes that directly influence drug effectiveness and toxicity, are direct manifestations of the daily oscillations of the cellular and biochemical processes taking place within the gastrointestinal, hepatic/biliary, and renal/urologic systems...
October 3, 2016: Drugs
Christopher J Sifuentes, Jung-Woong Kim, Anand Swaroop, Pamela A Raymond
Purpose: Zebrafish neurons regenerate from Müller glia following retinal lesions. Genes and signaling pathways important for retinal regeneration in zebrafish have been described, but our understanding of how Müller glial stem cell properties are regulated is incomplete. Mammalian Müller glia possess a latent neurogenic capacity that might be enhanced in regenerative therapies to treat degenerative retinal diseases. Methods: To identify transcriptional changes associated with stem cell properties in zebrafish Müller glia, we performed a comparative transcriptome analysis from isolated cells at 8 and 16 hours following an acute photic lesion, prior to the asymmetric division that produces retinal progenitors...
October 1, 2016: Investigative Ophthalmology & Visual Science
Wei-Wei Chen, Xia Zhang, Wen-Juan Huang
Pain and anxiety are the most common neurological responses to many harmful or noxious stimuli and their management clinically is often challenging. Many of the frequently used morphine-based drugs, non-steroid anti-inflammatory drugs and acetaminophen, while efficient for treating pain, lead to patients suffering from several unwanted side effects. Melatonin, produced from the pineal body is a hormone of darkness, is involved in the control of circadian rhythms, and exerts a number of pharmacological effects...
October 2016: Experimental and Therapeutic Medicine
Danilo E F L Flôres, Milene G Jannetti, Veronica S Valentinuzzi, Gisele A Oda
Synchronization of biological rhythms to the 24-hour day/night has long been studied with model organisms, under artificial light/dark cycles in the laboratory. The commonly used rectangular light/dark cycles, comprising hours of continuous light and darkness, may not be representative of the natural light exposure for most species, including humans. Subterranean rodents live in dark underground tunnels and offer a unique opportunity to investigate extreme mechanisms of photic entrainment in the wild. Here, we show automated field recordings of the daily light exposure patterns in a South American subterranean rodent, the tuco-tuco (Ctenomys aff...
October 4, 2016: Scientific Reports
Paola Ferri, Matteo Guadi, Luigi Marcheselli, Sara Balduzzi, Daniela Magnani, Rosaria Di Lorenzo
BACKGROUND: Shift work is considered necessary to ensure continuity of care in hospitals and residential facilities. In particular, the night shift is one of the most frequent reasons for the disruption of circadian rhythms, causing significant alterations of sleep and biological functions that can affect physical and psychological well-being and negatively impact work performance. OBJECTIVES: The aim of this study was to highlight if shift work with nights, as compared with day work only, is associated with risk factors predisposing nurses to poorer health conditions and lower job satisfaction...
2016: Risk Management and Healthcare Policy
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"