LD Cycle Research Articles

Light and dark rations and the photic entrainment of circadian locomotor activity patterns in the South American Silver Catfish (Rhamdia quelen, Quoy & Gaimard, 1824)

The aim of this study was to evaluate the daily rhythm of locomotor activity in Rhamdia quelen (R. quelen). A total of 30 fish were enrolled in the study and were equally divided in 10 groups and maintained in 100 liters tanks. The locomotor activity was measured in fish maintained under the LD 12:12 photoperiod regime; thereafter, the LD cycle was reversed to DL in order to study the resynchronization and to explore the endogenous pacemaker. Subsequently, the fish were subjected to constant conditions of light to test whether or not locomotor rhythms are regulated by the endogenous circadian clock. The effect of increasing light length and intensity was studied on daily rhythm of locomotor activity of fish. Our results showed that the R. quelen is a strictly diurnal species, the rhythm of locomotory activity resynchronized quickly after inverting the LD cycle and persist under free course LL, suggesting a circadian origin. The light showed a significant masking effect often blocking the expression of the biological rhythm. The strictly diurnal behavior is controlled directly by the photoperiod and maintained even under very dim light (30 lux).

0710 REPRODUCIBILITY OF CIRCADIAN VARIABLES (MEQ, MSF, DLMO, PHASE ANGLE, AND CIRCADIAN PERIOD) OVER MONTHS

We conducted two studies that were similar for the first 10 days (nature.com/articles/srep08381, nature.com/articles/srep36716), and determined each subject’s morningness-eveningness score (MEQ), Mid-sleep on Free Days (MSF) from the MCTQ, baseline dim light melatonin onset (DLMO), phase angle of entrainment, and free-running circadian period. Ten African-Americans (6 women, 4 men) and 8 European-Americans (2 women, 6 men) participated in both studies separated by 9 to 33 months (mean ± SD = 16 ± 7). They were 32.2 ± 6.7 years old at the first study. The purpose of this report is to examine the reproducibility of these circadian variables. Subjects slept in the lab on a fixed 8-h sleep schedule similar to their usual sleep schedule for 4 days, followed by a circadian phase assessment with 30 min saliva samples to calculate baseline DLMO. Phase angle was the interval from DLMO to bedtime. There were also 3 days of ultradian LD cycles producing forced desynchrony. Circadian period was determined from phase assessments before and after the days of ultradian LD cycles. For each circadian variable, we made scatter plots with identical x and y axes. Lines of unity showed when the variable was exactly the same in both studies. Lines parallel to and on each side of the line of unit showed how much the variable differed between the studies. We also calculated Pearson correlations for each variable. The MEQ score differed by less than 10 points between the two studies; MSF by 1 h or less, except for 2 subjects, baseline DLMO by 1 h or less except for 3 subjects, phase angle by 2 h or less, and circadian period by 0.3 h or less except for 2 subjects. All correlations were significant (p≤.0001), MEQ r=.85, MSF r=.78, baseline DLMO r=.81, phase angle r=.80, circadian period r=.78. A longer time between the two studies did not make the variables more different. In this small sample, there were no differences between men and women or between European and African-Americans in the stability of these variables. Circadian parameters were relatively stable over months. NIHR01NR007677.

MP82-11 THE MOLECULAR BIOLOGIC STUDY ABOUT THE CIRCADIAN RHYTHMIC CONTROL OF MICTURITION FUNCTION

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Basic Research & Pathophysiology II1 Apr 2017MP82-11 THE MOLECULAR BIOLOGIC STUDY ABOUT THE CIRCADIAN RHYTHMIC CONTROL OF MICTURITION FUNCTION Su Jin Kim, Young Sam Cho, and Khae Hawn Kim Su Jin KimSu Jin Kim More articles by this author , Young Sam ChoYoung Sam Cho More articles by this author , and Khae Hawn KimKhae Hawn Kim More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.2558AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We investigate the relationship between circadian rhythm and water metabolism and expression of circadian clock gene in peripheral bladder and central micturition centers. METHODS Normal mouse (C57BL/6J male; WT) and circadian gene knock-out mouse (per1-/-per2-/-; PDK) was used. Water intake and urine output according to the circadian rhythm was checked using metabolic cage in 12:12 LD photoperiodic cycle (LD cycle) and constant dark cycle (DD cycle) in both WT and PDK. Circadian clock gene expression rhythm in bladder was evaluated with the activation of Per2 promotor. Circadian expression of representative clock gene was analysed; Bmal1 and Rev-erba and rhythmic expression of circadian clock gene was analysed according to time in three main functional tissue related with micturition (detrusor smooth muscle, sphincter smooth muscle and urothelium) in both WT and PDK. Expression of clock gene in central micturition center was analysed; lumbar spinal cord, pontine micturition center (PMC) and ventrolateral periaqueductal gray (vlPAG), real-time RT-PCR was used in every 3 hours for 24 hours in DD cycle in both WT and PDK. RESULTS Water intake and urine output was increased in night-time of WT in LD and DD cycle. However this tendency was disappeared to PDK. Water intake and urine output was increased in night-time of WT in LD cycle and DD cycle was disappeared in PDK and this means that circadian rhythm is due to endogenous circadian rhythm not outside environment. We can observe the activation of Per2 promotor approximately 24 hours of rhythm. And this finding represents that bladder peripheral clock was well functioned. In case of WT, characteristic circadian expression pattern of clock gene in all three tissues. On the contrary, 24 hours of promoter activated rhythm was not observed in PDK. In spinal level, unlike PDK, clock gene expression rhythm was observed in WT. But, there was no definite rhythmicity of circadian expression pattern of clock gene in the upper region of central micturition center like PMC and vlPAG. CONCLUSIONS Endogenous circadian rhythm in water intake and urine output is exist approximately 24 hours. Bladder peripheral clock gene is existed in main functional tissue related with micturition. But in terms of central micturition center, we can find circadian clock gene expression only in lumbar spinal cord. Further study about the reason why absence of circadian clock in upper central micturition center and finding other circadian control mechanism in upper micturition center is needed. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1101 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Su Jin Kim More articles by this author Young Sam Cho More articles by this author Khae Hawn Kim More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The expression of the clock gene cycle has rhythmic pattern and is affected by photoperiod in the moth Sesamia nonagrioides.

To obtain clues to the link between the molecular mechanism of circadian and photoperiod clocks, we have cloned the circadian clock gene cycle (Sncyc) in the corn stalk borer, Sesamia nonagrioides, which undergoes facultative diapause controlled by photoperiod. Sequence analysis revealed a high degree of conservation among insects for this gene. SnCYC consists of 667 amino acids and structural analysis showed that it contains a BCTR domain in its C-terminal in addition to the common domains found in Drosophila CYC, i.e. bHLH, PAS-A, PAS-B domains. The results revealed that the sequence of Sncyc showed a similarity to that of its mammalian orthologue, Bmal1. We also investigated the expression patterns of Sncyc in the brain of larvae growing under long-day 16L: 8D (LD), constant darkness (DD) and short-day 10L: 14D (SD) conditions using qRT-PCR assays. The mRNAs of Sncyc expression was rhythmic in LD, DD and SD cycles. Also, it is remarkable that the photoperiodic conditions affect the expression patterns and/or amplitudes of circadian clock gene Sncyc. This gene is associated with diapause in S. nonagrioides, because under SD (diapause conditions) the photoperiodic signal altered mRNA accumulation. Sequence and expression analysis of cyc in S. nonagrioides shows interesting differences compared to Drosophila where this gene does not oscillate or change in expression patterns in response to photoperiod, suggesting that this species is an interesting new model to study the molecular control of insect circadian and photoperiodic clocks.

Entrainment of juvenile horseshoe crab activity to artificial tides

Juvenile American horseshoe crabs, Limulus polyphemus, express both daily and tidal rhythms. To determine if, and how, tidal cues influence the expression of these rhythms, we exposed 25 animals to artificial tides, and 17 to artificial tides with inundation, both with a 12:12 LD cycle. In the first experiment, 24% expressed daily rhythms of activity, 24% tidal rhythms, 12% a combination of the two, and the rest were arrhythmic. Under subsequent atidal conditions some expressed daily rhythms, but more were circatidal. In the second experiment, 6% expressed daily rhythms, 71% tidal, 12% a combination, and 12% were arrhythmic. Those expressing tidal rhythms were more active during flood/high tide, while daily animals tended to be nocturnal. Under subsequent constant conditions, the majority exhibited circatidal activity, with some expressing one activity bout per day. We conclude that juvenile horseshoe crabs entrain to artificial tides, with inundation cycles providing stronger cues than water depth changes.

Temporal Regulation of GABAA Receptor Subunit Expression: Role in Synaptic and Extrasynaptic Communication in the Suprachiasmatic Nucleus.

Recent molecular studies suggest that the expression levels of δ and γ2 GABAA receptor (GABAAR) subunits regulate the balance between synaptic and extrasynaptic GABA neurotransmission in multiple brain regions. We investigated the expression of GABAAδ and GABAAγ2 and the functional significance of a change in balance between these subunits in a robust local GABA network contained within the suprachiasmatic nucleus of the hypothalamus (SCN). Muscimol, which can activate both synaptic and extrasynaptic GABAARs, injected into the SCN during the day phase advanced the circadian pacemaker, whereas injection of the extrasynaptic GABAA superagonist 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP) had no effect on circadian phase. In contrast, injection of either THIP or muscimol during the night was sufficient to block the phase shifting effects of light. Gene expression analysis of the whole SCN revealed different temporal patterns in GABAAδ and GABAAγ2 mRNA expression. When examined across all subregions of the SCN, quantitative immunohistochemical analysis found no significant variations in GABAAδ protein immunoreactivity (IR) but did find significant variations in GABAAγ2 protein-IR in hamsters housed in either LD cycles or in constant darkness. Remarkably, significant interactions in the ratio of GABAAδ:GABAAγ2 subunits between lighting condition and circadian phase occurred only within one highly discrete anatomical area of the SCN; a region that functions as the input for lighting information from the retina. Taken together, these data support the hypothesis that the balance between synaptic and extrasynaptic GABAARs determines the functional response to GABA, and that this balance is differentially regulated in a region-specific manner.

Dexamethasone Modulates Nonvisual Opsins, Glucocorticoid Receptor, and Clock Genes in Danio rerio ZEM-2S Cells.

Here we report, for the first time, the differential cellular distribution of two melanopsins (Opn4m1 and Opn4m2) and the effects of GR agonist, dexamethasone, on the expression of these opsins and clock genes, in the photosensitive D. rerio ZEM-2S embryonic cells. Immunopositive labeling for Opn4m1 was detected in the cell membrane whereas Opn4m2 labeling shows nuclear localization, which did not change in response to light. opn4m1, opn4m2, gr, per1b, and cry1b presented an oscillatory profile of expression in LD condition. In both DD and LD condition, dexamethasone (DEX) treatment shifted the peak expression of per1b and cry1b transcripts to ZT16, which corresponds to the highest opn4m1 expression. Interestingly, DEX promoted an increase of per1b expression when applied in LD condition but a decrease when the cells were kept under DD condition. Although DEX effects are divergent with different light conditions, the response resulted in clock synchronization in all cases. Taken together, these data demonstrate that D. rerio ZEM-2S cells possess a photosensitive system due to melanopsin expression which results in an oscillatory profile of clock genes in response to LD cycle. Moreover, we provide evidence that glucocorticoid acts as a circadian regulator of D. rerio peripheral clocks.

Postnatal light alters hypothalamic-pituitary-adrenal axis function and induces a depressive-like phenotype in adult mice.

The postnatal light environment that a mouse experiences during the critical first three postnatal weeks has long-term effects on both its circadian rhythm output and clock gene expression. Furthermore, data from our lab suggest that postnatal light may also impact the hypothalamic-pituitary-adrenal (HPA) axis, which is a key regulator of stress. To test the effect of postnatal light exposure on adult stress responses and circadian rhythmicity, we raised mice under either 24-h light-dark cycles (LD), constant light (LL) or constant dark (DD) during the first three postnatal weeks. After weaning we then exposed all animals to LD cycles (basal conditions), followed by LL (stressed conditions) environments. We examined brain neuropeptide and glucocorticoid receptor (GR) expression, plasma corticosterone concentration rhythm and body temperature rhythm, together with depression- and anxiety-related behaviour. Results showed that LL- and DD-raised mice exhibited decreased GR expression in the hippocampus, increased plasma corticosterone concentration at the onset of the dark phase and a depressive phenotype when exposed to LD cycles later in life. Furthermore, LL-raised mice showed increased corticotrophin-releasing hormone mRNA expression in the paraventricular nucleus of the hypothalamus. When exposed to LL as adults, LL-raised mice showed a significant circadian rhythm of plasma corticosterone concentration, together with a shorter period and stronger circadian rhythm of body temperature compared to DD-raised mice. Taken together, these data suggest that altered postnatal light environments have long-term effects on the HPA axis and the circadian system, which can lead to altered stress responses and a depressive phenotype in adulthood.

Effect of differential photostimulation on induction of Fos-like immune-reactivity in the MBH region of Indian weaver bird

This study investigated the neuronal activation (c-fos) in the mediobasal hypothalamus (MBH) of the Indian weaver bird, after exposure to a single long-day. Wild-caught photosensitive birds were exposed to the short-days (LD 8L:16D). After four days of short-days photoperiod, the LD cycle was programmed such that the light illumination was continuous after zeitgeber time (ZT) 8. Birds were perfused on the same day at ZT 4 or ZT 20. Brains were processed for the immunohistochemistry of c-fos (Fos) in the MBH. We found a significant higher activation of Fos in neurons within the ventral tuberal division (containing infundibular nucleus) of the MBH, in group that received 20-h light than that received 4-h light on first long-day. But in the dorsal tuberal division, there was no noticeable difference in Fos-lir activation on after 4-h and 24-h light exposure. The results suggest that the ventral tuberal division of mediobasal hypothalamus is principally involved in detecting the photoperiodic information from the external environment, and hence, suggested as the key neural center, involved in the photoperiodic mechanism in Indian weaver bird.

Circadian rhythms of clock gene expression in Nile tilapia (Oreochromis niloticus) central and peripheral tissues: influence of different lighting and feeding conditions.

The present research aimed to investigate the existence of clock gene expression rhythms in tilapia, their endogenous origin, and how light and feeding cycles synchronize these rhythms. In the first experiment, two groups of fish were kept under an LD cycle and fed at two different time points: in the middle of the light (ML) or in the middle of the dark (MD) phase. In the second experiment, fish fed at ML was fasted and kept under constant lighting (LL) conditions for 1day. In both experiments, the samples from central (optic tectum and hypothalamus) and peripheral (liver) tissues were collected every 3h throughout a 24h cycle. The expression levels of clock genes bmal1a, clock1, per1b, cry2a, and cry5 were analyzed by quantitative PCR. All the clock genes analyzed in brain regions showed daily rhythms: clock1, bmal1a, and cry2a showed the acrophase approximately at the end of the light phase (ZT 8:43-11:22h), whereas per1b and cry5 did so between the end of the dark phase and the beginning of the light phase, respectively (ZT 21:16-4:00h). These rhythms persisted under constant conditions. No effect of the feeding time was observed in the brain. In the liver, however, the rhythms of clock1 and cry5 were influenced by feeding, and a shift was observed in the MD fish group (ZT 3:58h for clock1 and 11:20h for cry5). This study provides the first insights into the molecular clock of tilapia, a very important fish species for aquaculture. It also reveals the endogenous origin of clock gene rhythms and the ability of feeding time to shift the phase in some clock genes in the peripheral, but not the central, oscillator.

Timed food availability affects circadian behavior but not the neuropeptide Y expression in Indian weaverbirds exposed to atypical light environment

We tested the hypothesis whether daily food availability period would restore rhythmicity in individuals with disrupted circadian behavior with no effect on appetite regulation. Particularly, we investigated the effects of timed food availability on activity behavior, and Fos and neuropeptide Y expressions in Indian weaverbirds (Ploceus philippinus) under atypical light conditions. Initially, weaverbirds in 3 groups of 7–8 each were entrained to 7L:17D (25: <0.3lx) with food ad libitum. Thereafter, food availability was restricted for 7h such that it overlapped with the light period. After a week, 7L:17D was replaced with 3.5L: 3.5D (T7, group 1), 3.5L: 20.5D (T24, group 2) or constant dim light, LLdim (<0.3lx, group 3) for 5weeks. Food cycles synchronized the circadian activity behavior, albeit with group differences, but did not affect body mass, blood glucose levels or testis size. Further, Fos, not NPY mRNA or peptide, expression measured at ZT2 and ZT14 (ZT0=time of food given) showed significant group differences in the hippocampus, dorsomedial hypothalamus and infundibular nuclear complex. Another identical experiment examined after-effects of the 3 light conditions on persistence of the circadian rhythms. Weaverbirds exposed for 4weeks to identical food but different light conditions, as above, were released into the free-running condition of food ad libitum and LLdim. Circadian rhythms were decayed in birds previously exposed to T7 LD cycle. Overall, these results show that timed meal restores rhythmicity in individuals with circadian rhythm disruptions without involving neuropeptide Y, the key appetite regulatory molecule.

Intracranial Pressure Increases During Hindlimb Suspension

IntroductionOne of the responses following exposure to the microgravity spaceflight environment is a pronounced cephalic fluid shift. Recent evidence documents ocular changes in astronauts following long‐duration missions including optic disc edema, globe flattening, choroidal folds and hyperopic shifts. These changes are hypothesized to result from this cephalic fluid shift, as these ocular effects are similar to those seen in terrestrial Idiopathic Intracranial Hypertension (IIH) and are associated with increased intraocular pressure (IOP). Long duration missions are currently being undertaken on the International Space Station (ISS) and planning for manned missions to Mars has begun. This project aims to simulate long‐term microgravity cephalic fluid shift using a well‐established terrestrial rat model to provide a means for study of the mechanisms underlying ocular changes seen in spaceflight.MethodsWe are using the rat hindlimb suspension (HLS) model, functionally equivalent to human head‐down bedrest (a human terrestrial model of cephalic fluid shift), to examine the relationship between cephalic fluid shifts and the regulation of intracranial pressure (ICP) as well as visual system structure and function. As we are investigating the role of sex and age in these responses, the study includes three cohorts: young adult male, young adult female, and older middle‐age adult males, roughly equivalent to the ages of most mission‐ready astronauts. Rats are placed in HLS for up to 90 days, a time frame roughly equivalent to the proportion of an astronaut's lifespan that would be dedicated to an exploration class mission. This is followed by up to 90 days of post‐suspension recovery in a vivarium cage. All HLS subjects have age‐matched vivarium cage controls. All subjects have ad lib access to food and water. A 12:12 LD cycle is present. An implanted telemetry unit is used to measure body temperature, EEG and ICP. The pressure probe catheter is implanted in the lateral ventricle and continuous recordings are performed for one week prior to and after the start of HLS, after 30, 60 and 90 days of suspension and after 0, 30, 60 and 90 days of post‐suspension recovery. MRI images of the eyes and brain, and IOP measurements were also performed in additional animals exposed to HLS.Results and ConclusionsOur hypothesis is that HLS leads to 1.) increased ICP; which, when sustained over long time periods, results in 2.) increased IOP and can lead to 3.) morphological changes such as globe flattening of the eye as well as distension of the optic nerve complex. Results to date indicate a pronounced and sustained increase in ICP during the entire HLS period. Analysis of MRI images and IOPs suggest a pattern similar to that seen in astronauts on longer‐term missions as a subset of rats exhibit globe flattening, distension of the optic nerve complex, and increased IOP.Support or Funding InformationSupported by NASA Grant NNX13AD94G

Effect of Light Intensity and Wavelength on Diurnal Activity of the Banded Coral Shrimp Stenopus hispidus (Decapoda, Stenopodidae): A Possible Adaptation for a Cleaner Shrimp in Reef Environments

Most decapod crustaceans are nocturnal. However, because cleaner shrimp at cleaning stations act in concert with their hosts, they clean debris and parasites off the body surfaces of diurnal hosts during daytime. It is not known how cleaner shrimp physiologically accommodate diurnal environments and perform cleaning behaviors. We examined the effect of light cues on the daily rhythmicity of the banded coral shrimp Stenopus hispidus (Decapoda, Stenopodidae), a cleaner shrimp in coral reefs. Shrimp were individually kept in aquaria under conditions of 12-hr light and 12-hr darkness (LD) and constant darkness (DD). Double-plotted actogram analyses revealed that shrimp under LD were active during scotophase and inactive during photophase. Locomotor rhythms were observed in most shrimp under DD. Periodogram analyses showed a weak circadian rhythm in shrimp under DD. Our results show that this species is nocturnal and that its locomotor activity is controlled primarily by the LD cycle. Day-night differences in locomotor activity were reduced in shrimp under LD with weak irradiance, and they remained active during photophase. Shrimp under LD using blue or green light-emitting diode light, but not red light-emitting diode light, showed a day-inactive and night-active rhythmicity. These results indicate that this species can be active under environments with low green and blue spectra—for example, during twilight hours, at depth, or on cloudy days—even during daytime, and this weakness of the circadian clock may be advantageous in their role as cleaner shrimp. It is concluded that in addition to the presence of visiting hosts, light conditions at cleaning stations are likely to influence cleaning activity.

Static and fatigue mechanical behavior of three dental CAD/CAM ceramics

PurposeThe aim of this study was to measure the mechanical properties and fatigue behavior of three contemporary used dental ceramics, zirconia Cercon® (ZC), lithium disilicate e.max® CAD (LD), and polymer-infiltrated ceramic Enamic® (PIC). MethodsFlexural strength of each CAD/CAM ceramic was measured by three point bending (n=15) followed by Weibull analysis. Elastic modulus was calculated from the load–displacement curve. For cyclic fatigue loading, sinusoidal loading with a frequency of 8Hz with minimum load 3N were applied to these ceramics (n=24) using three point bending from 103 to 106 cycles. Fatigue limits of these ceramics were predicted with S–N fatigue diagram. Fracture toughness and Vickers hardness of the ceramics were measured respectively by single edge V-notch beam (SEVNB) and microindentation (Hv 0.2) methods. Chemical compositions of the materials׳ surfaces were analyzed by EDS, and microstructural analysis was conducted on the fracture surfaces by SEM. One-way ANOVA was performed and the level of significance was set at 0.05 to analyze the numerical results. ResultsThe mean flexural strength of ZC, LD, and PIC was respectively 886.9, 356.7, and 135.8MPa. However, the highest Weibull modulus belonged to PIC with 19.7 and the lowest was found in LD with 7.0. The fatigue limit of maximum load for one million cycles of ZC, LD, and PIC was estimated to be 500.1, 168.4, and 73.8GPa. The mean fracture toughness of ZC, LD, and PIC was found to be respectively 6.6, 2.8, and 1.4MPam1/2, while the mean Vickers hardness was 1641.7, 676.7, and 261.7Hv. Fracture surfaces followed fatigue loading appeared to be smoother than that after monotonic loading. ConclusionsMechanical properties of ZC were substantially superior to the two other tested ceramics, but the scattering of data was the least in PIC. The fatigue limit was found to be approximately half of the mean flexural strength for all tested ceramics.

Evidence for age-related changes in the circadian activity rhythm of the diurnal primate Callithrix jacchus: a case report

Many cross-sectional studies have shown that circadian rhythms change with age, but such age-related modifications are gradual and may be insufficiently described by cross-sectional studies. In this case study, circadian activity rhythm (CAR) was evaluated longitudinally, in both LD (12:12) and LL conditions, on two occasions in a single male marmoset: when ‘adult’ (3 y.o.) and when ‘old’ (9 y.o.). When adult, the CAR synchronized with positive phase angles for the onset and offset of activity. In LL, the rhythm free-ran with τ < 24 h. When old, the animal showed a significant phase delay of its activity rhythm with respect to the LD cycle (t-test, p < 0.01) and a reduction on total daily activity (t-test, p < 0.01), with signs of lesser stability, greater fragmentation and some loss of photic synchronization. In LL, the period free-ran with τ > 24 h. We conclude that aging is associated with attenuation of photic synchronization and expression of CAR in LL in the marmoset. Further studies with a larger number of individuals are needed to confirm these findings.

Unique food-entrained circadian rhythm in cysteine414-alanine mutant mCRY1 transgenic mice.

Food availability is a potent environmental cue that directs circadian locomotor activity in rodents. Daily scheduled restricted feeding (RF), in which the food available time is restricted for several hours each day, elicits anticipatory activity. This food-anticipatory activity (FAA) is controlled by a food-entrainable oscillator (FEO) that is distinct from the suprachiasmatic nucleus (SCN), the master pacemaker in mammals. In an earlier report, we described generation of transgenic (Tg) mice ubiquitously overexpressing cysteine414-alanine mutant mCRY1. The Tg mice displayed long locomotor free-running periods (approximately 28 h) with rhythm splitting. Furthermore, their locomotor activity immediately re-adjusted to the advance of light–dark cycles (LD), suggesting some disorder in the coupling of SCN neurons. The present study examined the restricted feeding cycle (RF)-induced entrainment of locomotor activity in Tg mice in various light conditions. In LD, wild-type controls showed both FAA and LD-entrained activities. In Tg mice, almost all activity was eventually consolidated to a single bout before the feeding time. The result suggests a possibility that in Tg mice the feeding cycle dominates the LD cycle as an entrainment agent. In constant darkness (DD), wild-type mice exhibited robust free-run activity and FAA during RF. For Tg mice, only the rhythm entrained to RF was observed in DD. Furthermore, after returning to free feeding, the free-run started from the RF-entrained phase. These results suggest that the SCN of Tg mice is entrainable to RF and that the mCRY1 mutation alters the sensitivity of SCN to the cycle of nonphotic zeitgebers.Electronic supplementary materialThe online version of this article (doi:10.1007/s41105-016-0050-1) contains supplementary material, which is available to authorized users.

Immunomodulation by classical conditioning in NZB/W (F1) mice: Lifespan and diurnal variation

Systemic Lupus Eritematosus (SLE) is a systemic inflammatory disease often treated with the agent cyclophosphamide (CY), known by provoking important adverse reactions to the organism. Ader and Cohen have demonstrated an alternative way of administrating this agent based on pavlovian conditioning, in order to reduce the aggression caused by CY. Considering the influence of the temporal organization on learning and memory processes, the purpose of this study was to understand the temporal aspects involved in the conditioned immunomodulation. In a search for circadian modulation, we selected NZB/W (F1) female mice, a strain that spontaneously develop SLE. Divided into two major groups, the animals were submitted, in different phases of day, to a classical conditioning immunomodulation protocol, consisting in weekly parings of saccharin solution and CY injections. The success of the paradigm was evaluated by comparing lifespan among the groups. Simultaneously, it was monitored the water intake behavior, in order to correlate the stability of two rhythmic parameters, amplitude and spectral power density of the 24-h rhythm, with the progression of SLE. Our results indicate that mice could benefit from the conditioning task performed either in the light phase or in the dark phase of the LD cycle, as expressed by an increased lifespan. Concerning the rhythmic parameters, there was evidence of association between the rhythmic stability and the evolution of SLE, demonstrated by the maintenance of healthy levels of amplitude and spectral potency of the 24-h rhythm in animals exposed to the conditioning paradigm.

Continuous Treatment with Lenalidomide Plus Low-Dose Dexamethasone (Ld) Versus Ld Induction Followed By Autologous Stem Cell Transplant (ASCT) in Patients with Newly Diagnosed Multiple Myeloma (NDMM): A Pooled Analysis of Two Randomized Clinical Trials

Background: High-dose chemotherapy followed by ASCT remains the standard of care for patients aged ≤75 years with NDMM. The ability of novel agents, such as lenalidomide and bortezomib, to produce treatment response rates comparable to those seen with ASCT has raised questions about the necessity for upfront ASCT in transplant-eligible NDMM patients. This analysis aimed to compare the efficacy and safety of continuous Ld versus Ld+ASCT in patients with NDMM.Methods: Data were pooled from two randomized clinical trials (NCT01731886 and NCT00807599) that compared Ld alone versus Ld+ASCT in NDMM patients aged ≤75 years. Patients received four 28-day cycles of Ld (lenalidomide 25mg daily on days 1-21; dexamethasone 40mg on days 1, 8, 15, and 22) followed by stem-cell mobilization and collection, and either a) Arm A: continuous Ld (an additional 4 cycles +/- lenalidomide maintenance in NCT01731886, or continuous lenalidomide at the last tolerated dose until disease progression plus dexamethasone 20mg for 1 year following treatment initiation in NCT00807599); or b) Arm B: ASCT conditioned with high-dose melphalan, and followed by lenalidomide maintenance therapy. In both trials, patients were withdrawn if they developed progressive disease (PD) at any time, or had stable disease (SD) after cycle 4 of Ld induction. We evaluated overall response rate (ORR; defined as a partial response or better), progression-free survival (PFS), overall survival (OS), and adverse event (AE) incidence rates, focusing on those randomized patients who responded to 4 cycles of Ld induction.Results: Sixty patients were enrolled into NCT01731886, and 63 into NCT00807599. The analysis included a total of 85 patients who had been randomized and achieved a response to 4 cycles of Ld induction: 41 in Arm A, and 44 in Arm B. Mean ages in Arm A versus Arm B were 61.8 versus 61.7 years; median (range) follow-up times were 3.97 (0.27-6.19) versus 3.71 (0.16-5.66) years. Baseline cytogenetic risk profiles were similar overall, although Arm A contained a higher percentage of intermediate-risk patients (17.1% versus 11.4%). More than half of all patients included in the analysis had International Staging System stage 1 disease: 63.4% of patients in Arm A, and 47.7% of those in Arm B. Median PFS was similar with the two treatment approaches: 4.3 versus 4.4 years (Figure 1; p = 0.9107). OS also did not differ significantly between the two arms (Figure 2). As expected, both treatment regimens were well tolerated. Clinically significant grade 3 and 4 AEs occurring outside of the transplant period included the following: anemia (17.1% Arm A versus 15.9% Arm B); neutropenia (36.6% versus 38.6%); thrombocytopenia (17.1% versus 18.4%); infectious complications (14.6% versus 27.3%); thromboembolic events (7.3% versus 6.8%); and secondary malignancies (7.3% versus 4.5%).Conclusions: The findings of this pooled analysis suggest that, in transplant-eligible patients responsive to Ld induction, continuous Ld results in similar PFS and OS to Ld+ASCT. Larger phase III trials addressing this question are awaited. [Display omitted] [Display omitted] DisclosuresLentzsch:Celgene: Consultancy; BMS: Consultancy; Novartis: Consultancy; Janssen: Consultancy; Axiom: Honoraria. Landau:Janssen: Consultancy; Spectrum Pharmaceuticals: Honoraria; Prothena: Consultancy, Honoraria; Janssen: Consultancy; Onyx: Honoraria, Research Funding; Takeda: Research Funding. Lesokhin:Efranat: Consultancy; Genentech: Research Funding; Aduro: Consultancy; Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding. Kewalramani:Celgene: Consultancy; Abbvie: Consultancy; Getchell v Doon East Community Hospital, Alfred Wakeman et al.: Consultancy. Comenzo:Karyopharm: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Prothena: Research Funding; Takeda Millennium: Research Funding; Takeda Millennium: Membership on an entity's Board of Directors or advisory committees. Landgren:Celgene: Honoraria; Bristol-Myers Squibb: Honoraria; Medscape: Honoraria; Onyx: Honoraria; International Myeloma Foundation: Research Funding; Onyx: Research Funding; BMJ Publishing: Consultancy; BMJ Publishing: Honoraria; Medscape: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Onyx: Consultancy. Hassoun:Novartis: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Research Funding.

Two-phase photoperiodic cultivation of algal–bacterial consortia for high biomass production and efficient nutrient removal from municipal wastewater

This study investigated the photoperiodic effects on the biomass production and nutrient removal in the algal–bacterial wastewater treatment, under the following three conditions: (1) a natural 12h:12h LD cycle, (2) a dark-elongated 12h:60h LD cycle, and (3) a two-phase photoperiodic 12h:60h LD, followed by 12h:12h LD cycles. The two-phase photoperiodic operation showed the highest dry cell weight and lipid productivity (282.6mgL−1day−1, 71.4mgL−1day−1) and most efficient nutrient removals (92.3% COD, 95.8% TN, 98.1% TP). The genetic markers and sequencing analyses indicated rapid increments of bacteria, subsequent growths of Scenedesmus, and stabilized population balances between algae and bacteria. In addition, the two-phase photoperiod provided a higher potential for the algal–bacterial consortia to utilize various organic carbon substrates.

Circadian Disruption and Diet-Induced Obesity Synergize to Promote Development of β-Cell Failure and Diabetes in Male Rats.

There are clear epidemiological associations between circadian disruption, obesity, and pathogenesis of type 2 diabetes. The mechanisms driving these associations are unclear. In the current study, we hypothesized that continuous exposure to constant light (LL) compromises pancreatic β-cell functional and morphological adaption to diet-induced obesity leading to development of type 2 diabetes. To address this hypothesis, we studied wild type Sprague Dawley as well as Period-1 luciferase reporter transgenic rats (Per1-Luc) for 10 weeks under standard light-dark cycle (LD) or LL with concomitant ad libitum access to either standard chow or 60% high-fat diet (HFD). Exposure to HFD led to a comparable increase in food intake, body weight, and adiposity in both LD- and LL-treated rats. However, LL rats displayed profound loss of behavioral circadian rhythms as well as disrupted pancreatic islet clock function characterized by the impairment in the amplitude and the phase islet clock oscillations. Under LD cycle, HFD did not adversely alter diurnal glycemia, diurnal insulinemia, β-cell secretory function as well as β-cell survival, indicating successful adaptation to increased metabolic demand. In contrast, concomitant exposure to LL and HFD resulted in development of hyperglycemia characterized by loss of diurnal changes in insulin secretion, compromised β-cell function, and induction of β-cell apoptosis. This study suggests that circadian disruption and diet-induced obesity synergize to promote development of β-cell failure, likely mediated as a consequence of impaired islet clock function.