Altered Grooming Cycles in Transgenic Drosophila

Head grooming in Drosophila consists of repeated sweeps of the legs across the head, comprising regular cycles. We used the GAL4-UAS system to study the effects of overexpressing shibirets1 and of Adar knockdown via RNA interference, on the period of head-grooming cycles in Drosophila. Overexpressing shibirets1 interferes with synaptic vesicle recycling and thus with cell communication, while Adar knockdown reduces RNA editing of neuronal transcripts for a large number of genes. All transgenic flies and their controls were tested at 22° to avoid temperature effects; in wild type, cycle frequency varied with temperature with a Q10 of 1.3. Two experiments were performed with transgenic shibirets1: (1) each fly was heat-shocked for 10 min at 30° immediately before testing at 22° and (2) flies were not heat shocked. In both experiments, cycle period was increased when shibirets1 was overexpressed in all neurons, but was not increased when shibirets1 was overexpressed in motoneurons alone. We hypothesize that grooming cycles in flies overexpressing shibirets1 are lengthened because of synaptic impairment in neural circuits that control head-grooming cycles. In flies with constitutive, pan-neuronal Adar knockdown, cycle period was more variable within individuals, but mean cycle period was not significantly altered. We conclude that RNA editing is essential for the maintenance of within-individual stereotypy of head-grooming cycles.

Britain's harnessing of Thames river from the perspective of peace studies and its enlightenment-research based on the background of great stink in London

In recent years, novel coronavirus has been rampant all over the world, and environmental pollution has increasingly become an unavoidable problem. The history of human development seems to be always accompanied by environmental pollution. In 1858, the appearance of the big stink in London reflected the serious pollution of Thames River in the process of industrialization. The pollution of the Thames River has aroused widespread concern of all groups in Britain, and the long road of pollution control in Britain has brought profound historical lessons. However, what future generations need to really learn from it is to get rid of the dilemma of pollution before treatment. This study takes the Thames River as an analogy, positioning human destruction of nature as the intertwined of history, and pushing the debate on environmental science, peace science, and history to a climax in order to reach wise recommendations on environmental protection, which is very necessary on the contemporary stage. While promoting the progress of human civilization, strengthening the protection of the environment may be the best way to break the traditional dilemma.

Period Poverty: A Neglected Public Health Issue

Period poverty is a global community health dilemma that has long been overlooked. This condition is described as having insufficient access to menstrual products, education, and sanitation facilities. Briefly, period poverty means that millions of women are subjected to injustice and inequity due to menstruation. This review aimed to explore the definition, challenges, and effects of period poverty on the community, especially among women at their productive ages. In addition, suggestions to minimize the impact of period poverty are discussed. A search strategy was applied using the keywords "period poverty," "period equity," "period poverty," and "menstrual hygiene" in Google Scholar, ScienceDirect, SpringerLink, MEDLINE, and PubMed electronic databases, journals, and articles on relevant topics. Trained researchers conducted a keyword search from January 2021 to June 2022. Based on the reviewed studies, it has been proven that many countries are still affected by the period stigma and taboo, inadequate exposure to menstrual health and its management, lack of education about menstruation, and shortage of access to menstrual products and facilities. The next step is to reduce and slowly eliminate the period poverty issue by conducting more research to increase clinical evidence and future references. This narrative review could inform policymakers of the magnitude of the burden related to this issue and guide them to develop effective strategies to minimize the impact of poverty, especially during the challenging years of the post-coronavirus disease 2019 era.

Cell-Based Phenotypic Screens to Discover Circadian Clock-Modulating Compounds

There is increasing demand to control circadian clock functions in a conditional manner for deeper understanding of the circadian system as well as for potential treatment of clock-related diseases. Small-molecule compounds provide powerful tools to reveal novel functions of target proteins in the circadian clock mechanism, and can be great therapeutic candidates. Here we describe the detailed methods of measuring cellular circadian rhythms in a high-throughput manner for chemical screening to identify compounds that affect circadian rhythms by targeting clock-related proteins.

Protein interaction networks of the mammalian core clock proteins

Circadian rhythm is a 24-h cycle that regulates the biochemical and behavioral changes of organisms. It controls a wide range of functions, from gene expression to behavior, allowing organisms to anticipate daily changes in their environment. In mammals, circadian rhythm is generated by a complex transcriptional and translational feedback loop mechanism. The binding of CLOCK/BMAL1 heterodimer to the E-box of DNA located within the promoter region initiates transcription of clock control genes including the transcription of the other two core clock genes of Periods (Pers) and Cryptochromes (Crys). Then PERs and CRYs along with casein kinase 1ɛ/Δ translocate into the nucleus where they suppress CLOCK/BMAL1 transactivation and, in turn, clock-regulated gene expression. Various clock components must be operational to aid in their stabilization and period extension in circadian rhythm. In this review, we have highlighted the recent progress for the core clock interacting proteins to maintain and to stabilize circadian rhythm in mammals.

Comparison of the clinical presentation across two waves of COVID-19: a retrospective cohort study

BACKGROUND

Only a few studies have performed comprehensive comparisons between hospitalized patients from different waves of COVID-19. Thus, we aimed to compare the clinical characteristics and laboratory data of patients admitted to the western part of Denmark during the first and second waves of COVID-19 in 2020. Furthermore, we aimed to identify risk factors for critical COVID-19 disease and to describe the available information on the sources of infection.

METHODS

We performed a retrospective study of medical records from 311 consecutive hospitalized patients, 157 patients from wave 1 and 154 patients from wave 2. The period from March 7 to June 30, 2020, was considered wave 1, and the period from July 1st to December 31, 2020, was considered wave 2. Data are presented as the total study population, as a comparison between waves 1 and 2, and as a comparison between patients with and without critical COVID-19 disease (nonsurvivors and patients admitted to the intensive care unit (ICU)).

RESULTS

Patients admitted during the first COVID-19 wave experienced a more severe course of disease than patients admitted during wave 2. Admissions to the ICU and fatal disease were significantly higher among patients admitted during wave 1 compared to wave 2. The percentage of patients infected at hospital decreased in wave 2 compared to wave 1, whereas more patients were infected at home during wave 2. We found no significant differences in sociodemographics, lifestyle information, or laboratory data in the comparison of patients from waves 1 and 2. However, age, sex, smoking status, comorbidities, fever, and dyspnea were identified as risk factors for critical COVID-19 disease. Furthermore, we observed significantly increased levels of C-reactive protein and creatinine, and lower hemoglobin levels among patients with critical disease.

CONCLUSIONS

At admission, patients were more severely ill during wave 1 than during wave 2, and the outcomes were worse during wave 1. We confirmed previously identified risk factors for critical COVID-19 disease. In addition, we found that most COVID-19 infections were acquired at home.

Bioinformatics and Systems Biology of Circadian Rhythms: BIO_CYCLE and CircadiOmics

Circadian rhythms are fundamental to biology and medicine and today these can be studied at the molecular level in high-throughput fashion using various omic technologies. We briefly present two resources for the study of circadian omic (e.g. transcriptomic, metabolomic, proteomic) time series. First, BIO_CYCLE is a deep-learning-based program and web server that can analyze omic time series and statistically assess their periodic nature and, when periodic, accurately infer the corresponding period, amplitude, and phase. Second, CircadiOmics is the larges annotated repository of circadian omic time series, containing over 260 experiments and 90 million individual measurements, across multiple organs and tissues, and across 9 different species. In combination, these tools enable powerful bioinformatics and systems biology analyses. The are currently being deployed in a host of different projects where they are enabling significant discoveries: both tools are publicly available over the web at: http://circadiomics.ics.uci.edu/ .

Nasopharyngeal malignancies in Denmark diagnosed from 1980 to 2014

OBJECTIVES

Nasopharyngeal malignancies are reported having decreasing incidence and reduced mortality. This study provides a nationwide update of the incidence and survival in Denmark.

MATERIALS AND METHODS

The Danish Cancer Registry (DCR) and Central Population Register (CPR) were used to identify all patients registered with nasopharyngeal malignancies between 1980 and 2014 in Denmark. We evaluated the age-adjusted incidence rate (AAIR), average annual percent change (AAPC) and relative survival (RS) and also constructed age-population-cohort (APC) models.

RESULTS

911 patients were identified with a male:female ratio of 2.2:1, a median age of 57.7 years (range 2.8-98.3 years) and an overall median follow-up time of 2.7 years (range 0-37 years). The AAIR was 0.39 cases per 100 000 in 1980 and 0.28 cases per 100 000 in 2014 with an AAPC of -3.2 (95% CI: -7.5; 1.2, p = 0.1). The overall 1-year and 5-year RS rates were 76.3% and 42.1%, respectively. We found a significant age effect in the APC model for the incidence of nasopharyngeal malignancies, but no significant cohort or period effects.

CONCLUSION

The incidence of nasopharyngeal carcinomas has slightly decreased over the last four decades, however insignificantly. Meanwhile, the relative survival has increased significantly in Denmark since 1980. The cause of improved relative survival might be attributed to altered treatment practices.

[Methotrexate: How long between administration and conception?]

In women of childbearing age, methotrexate is prescribed in many indications other than cancer, either chronically (psoriasis, rheumatoid arthritis, IBD, etc.) or occasionally (ectopic pregnancies). The time given to these patients to consider pregnancy is currently subject to great variability depending on the sources. Analysis of the available objective evidence suggests that it is not justified to unnecessarily lengthen this period, and that conceiving the menstrual cycle following stopping methotrexate is quite possible.

Serum factor(s) from lung adenocarcinoma patients regulates the molecular clock expression

Lung cancer is a leading cause of cancer-associated deaths worldwide. Lung cancer may lead to circadian disruption, which could contribute to the development of lung cancer. Recently, several studies using animal models indicated that tumors influence systemic circadian homeostasis in remote tissues. However, it is unclear whether carcinoma of the lungs influences remote circadian rhythm, whether this effect exists in humans, and whether signals from the tumor travel through the blood. In this study, we used a cell-based assay to determine whether serum from patients with lung adenocarcinoma could modulate the molecular clock. We found that the daily oscillation period of Bmal1 was significantly lengthened following treatment with serum from untreated lung adenocarcinoma patients. In addition, heat inactivation of this serum abolished the effect, suggesting that a heat-sensitive circulating factor(s) is present in the serum of untreated lung adenocarcinoma patients. Using real-time PCR, we also examined the mRNA abundance of Bmal1, Cry1, and Per1 in human osteosarcoma u2os cell line, HUVECs and A549 cell lines. The expression of Bmal1 was changed in A549 cells in the presence of sera from lung adenocarcinoma patients. Our study revealed a direct effect of serum from lung adenocarcinoma patients on the molecular clock.

Perioperative SARS-CoV-2 infection among women undergoing major gynecologic cancer surgery in the COVID-19 era: A nationwide, cohort study from Turkey

OBJECTIVE

The objective of this study was to determine the rate of perioperative SARS-CoV-2 infection among gynecologic cancer patients undergoing major surgery.

METHODS

The database of the Turkish Ministry of Health was searched in order to identify all consecutive gynecologic cancer patients undergoing major surgery between March 11, 2020 and April 30, 2020 for this retrospective, nationwide, cohort study. The inclusion criteria were strictly founded on a final histopathological diagnosis of a malignant gynecologic tumor. COVID-19 cases were diagnosed by reverse transcriptase- polymerase chain reaction testing for SARS-CoV-2. The rate of perioperative SARS-CoV-2 infection and the 30-day mortality rate of COVID-19 patients were investigated.

RESULTS

During the study period, 688 women with gynecologic cancer undergoing major surgery were identified nationwide. The median age of the patients was 59 years. Most of the surgeries were open (634/688, 92.2%). There were 410 (59.6%) women with endometrial cancer, 195 (28.3%) with ovarian cancer, 66 (9.6%) with cervical cancer, 14 (2.0%) with vulvar cancer and 3 (0.4%) with uterine sarcoma. The rate of SARS-CoV-2 infections confirmed within 7 days before or 30 days after surgery was 46/688 (6.7%). All but one woman was diagnosed postoperatively (45/46, 97.8%). The rates of intensive care unit admission and invasive mechanical ventilation were 4/46 (8.7%) and 2/46 (4.3%), respectively. The 30-day mortality rate was 0%.

CONCLUSION

In the COVID-19 era, gynecologic cancer surgery may be performed with an acceptable rate of perioperative SARS-CoV-2 infection if the staff and the patients strictly adhere to the established infection control measures.

Changing epidemiology and outcomes of acute kidney injury in Brazilian patients: a retrospective study from a teaching hospital

PURPOSE

While considerable information is available on acute kidney injury (AKI) in North America and Europe, large comprehensive epidemiologic studies on AKI from Latin America and Asia are still lacking. The present study aimed to evaluate the epidemiology and outcomes of AKI in patients evaluated by nephrologists in a Brazilian teaching hospital.

METHODS

We performed a large retrospective observational study that looked into the epidemiology of AKI and its effect on patient outcomes across time periods. For comparison purposes, patients were divided into two groups according to the year of follow up: 2011-2014 and 2015-2018.

RESULTS

We enrolled 7976 AKI patients and, after excluding patients with chronic kidney disease stages 4 and 5, kidney transplant recipients and those with incomplete data, 5428 AKI patients were included (68%). The maximum AKI stage was 3 (50.6%), and there was a mortality rate of 34.3% (1865 patients). Dialysis treatment was indicated in 928 patients (17.1%). Patient survival improved along the study periods, and patients treated in 2015-2018 had a relative risk death reduction of 0.89 (95% CI 0.81-0.98, p = 0.02). The independent risk factors for mortality were sepsis, > 65 years of age, admission to the intensive care unit, AKI-KDIGO 3, recurrent AKI, no metabolic and fluid demand to capacity imbalance (as a dialysis indication), and the period of treatment.

CONCLUSION

We observed an improvement in AKI patient survival over the years, even after correction for several confounders and using a competing risk approach. Identification of risk factors for mortality can help in decision-making for timely intervention, leading to better clinical outcomes.

Variations in strength-related measures during the menstrual cycle in eumenorrheic women: A systematic review and meta-analysis

OBJECTIVES

To systematically review the current body of research that has investigated changes in strength-related variables during different phases of the menstrual cycle in eumenorrheic women.

DESIGN

Systematic review and meta-analysis.

METHODS

A literature search was conducted in Pubmed, SPORTDiscus and Web of Science using search terms related to the menstrual cycle and strength-related measures. Two reviewers reached consensus that 21 studies met the criteria for inclusion. Methodological rigour was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Random effects meta-analyses were used to compare the early-follicular, ovulatory and mid-luteal phases for maximal voluntary contraction, isokinetic peak torque, and explosive strength.

RESULTS

The assessment of study quality showed that a high level of bias exists in specific areas of study design. Non-significant and small or trivial effect sizes (p≥0.26, Hedges g≤0.35) were identified for all strength-related variables in each comparison between phases. 95% confidence intervals for each comparison suggested the uncertainty associated with each estimate extends to a small effect on strength performance with unclear direction (-0.42≤g≤0.48). The heterogeneity for each comparison was also small (p≥0.83, I²=0%).

CONCLUSIONS

Strength-related measures appear to be minimally altered (g≤0.35) by the fluctuations in ovarian sex hormones that occur during the menstrual cycle. This finding should be interpreted with caution due to the methodological shortcomings identified by the quality assessment.

Chemical modulation of circadian rhythms and assessment of cellular behavior via indirubin and derivatives

Circadian rhythms are critical regulators of many physiological and behavioral functions. The use and abilities of small molecules to affect oscillations have recently received significant attention. These manipulations can be reversible and tunable, and have been used to study various biological mechanisms and molecular properties. Here, we outline procedures for assessment of cellular circadian changes following treatment with small molecules, using luminescent reporters. We describe reporter generation, luminometry experiments, and data analysis. Protocols for studies of accompanying effects on cells, including motility, viability, and anchorage-independent proliferation assays are also presented. As examples, we use indirubin-3'-oxime and two derivatives, 5-iodo-indirubin-3'-oxime and 5-sulfonic acid-indirubin-3'-oxime. In this case study, we analyze effects of these compounds on Bmal1 and Per2 (positive and negative core circadian elements) oscillations and provide step-by-step protocols for data analysis, including removal of trends from raw data, period estimations, and statistical analysis. The reader is provided with detailed protocols, and guidance regarding selection of and alternative approaches.

[On 'Negative control methods': related principles, methods and applications]

Negative control methods (NCM) are developed based on the idea that negative controls should be tested with negative results. It also extends to the multiple comparison groups and used for specificity of association in population studies. Negative controls do not take part in studying the causal hypothesis but sharing the same potential bias structures. Under different purposes, NCM can be divided into methods on negative exposure, negative period or negative outcome controls. They are mainly used to detect and control bias, such as: selection bias, confounding bias and measurement bias, but leaving the sample size at secondary importance. Rational application of NCM can help improving the accuracy of causal inference in both experimental and observational processes.

Prevalence of sexual experience among Korean adolescent: age-period-cohort analysis

OBJECTIVES

Since exposure to sexual content and early sexual initiation among adolescents have become serious social issues in Korea, an in-depth analysis of trends in the prevalence of sexual experience among Korean adolescents is necessary to project the trends and policies required for the next 10 years. The objective of this study was to identify the contributions of age, period, and birth cohort effects on the prevalence of sexual experience in Korean adolescents.

METHODS

We analyzed age-specific, period-specific, and birth cohort–specific trends in the prevalence of sexual experience among 911,502 adolescents (469,593 boys, 51.5%; 441,909 girls, 48.5%) aged 12 years to 17 years from the 2006 to 2017 Korean Youth Risk Behavior Web-based Survey. Joinpoint regression analysis was conducted to examine significant changes in the prevalence of sexual experience and to find the optimal number and location of places where trends changed.

RESULTS

The prevalence of sexual experience generally increased with age in all periods in both boys and girls. In boys, the prevalence of sexual experience increased in recent periods, especially in the age group of 12-13 years, while the prevalence of sexual experience decreased in the age group of 16-17 years. In girls, the age group of 12-13 years showed an increased prevalence of sexual experience in recent periods. However, the prevalence showed a decreasing trend in the age group of 16-17 years.

CONCLUSIONS

In boys and girls, sexual experience increased with age, although this tendency has slowed in recent cohorts. Therefore, early sex education is needed.

Brief freezing steps lead to robust immunofluorescence in the Drosophila nervous system

Drosophila melanogaster possesses a complex nervous system, regulating sophisticated behavioral outputs, that serves as a powerful model for dissecting molecular mechanisms underlying neuronal function and neurodegenerative disease. Immunofluorescence techniques provide a way to visualize the spatiotemporal organization of these networks, permitting observation of their development, functional location, remodeling and, eventually, degradation. However, basic immunostaining techniques do not always result in efficient antibody penetration through the brain, and supplemental techniques to enhance permeability can compromise structural integrity, altering spatial organization. Here, slow freezing of brains is shown to facilitate antibody permeability without loss of antibody specificity or brain integrity. To demonstrate the advantages of this freezing technique, the results of two commonly used permeation methods - detergent-based and partial proteolytic digestion - are compared.

Nuclear Envelope Protein MAN1 Regulates the Drosophila Circadian Clock via Period

Almost all organisms exhibit ~24-h rhythms, or circadian rhythms, in a plentitude of biological processes. These rhythms are driven by endogenous molecular clocks consisting of a series of transcriptional and translational feedback loops. Previously, we have shown that the inner nuclear membrane protein MAN1 regulates this clock and thus the locomotor rhythm in flies, but the mechanism remains unclear. Here, we further confirmed the previous findings and found that knocking down MAN1 in the pacemaker neurons of adult flies is sufficient to lengthen the period of the locomotor rhythm. Molecular analysis revealed that knocking down MAN1 led to reduced mRNA and protein levels of the core clock gene period (per), likely by reducing its transcription. Over-expressing per rescued the long period phenotype caused by MAN1 deficiency whereas per mutation had an epistatic effect on MAN1, indicating that MAN1 sets the pace of the clock by targeting per.

Microcurrent stimulation activates the circadian machinery in mice

The circadian rhythm, which regulates various body functions, is transcriptionally controlled by a series of clock gene clusters. The clock genes are related to the pathology of various kinds of diseases, which in turn, is related to aging. Aging in humans is a worldwide problem; it induces sleep disorders and disruption of the circadian rhythm. It also decreases ocular vision and appetite and weakens the synchronization of clock genes by light and food. Therefore, a simple method for the synchronization of clock genes in the body is required. In this study, the influence of microcurrent stimulation (MCS) on the circadian machinery in wild-type (WT) and Clock mutant (Clk/Clk) mice was investigated. MCS induced Per1 mRNA expression in cultured mouse astrocytes; cAMP response element (CRE) in the Per1 mouse promoter was found to be important for the induction of Per1 mRNA. In addition, MCS increased the Per1 mRNA levels in mouse livers and caused the phase advance of the Per1 expression rhythm. The protein expression rhythm of phosphor-cAMP response element-binding protein (pCREB) was altered and the phase of expression of pCREB protein advanced. Finally, the influence of MCS on the locomotor activity rhythm in WT and Clk/Clk mice was investigated. MCS caused the phase advance of the locomotor activity rhythm in WT and Clk/Clk mice. The results of this study indicate that MCS activated the clock machinery in mice; MCS may thus improve the quality of new treatment modalities in the future.

Imaging In Acute Bronchiolitis: Evaluation of The Current Practice In a Kuwaiti Governmental Hospital and Its Possible Impact on Hospitalization Period

BACKGROUND AND OBJECTIVES

Guidelines for acute bronchiolitis recommend primarily supportive care, but unnecessary treatment measures remain well documented. This study was designed to assess the Al-Adan Hospital pediatricians` attitude towards imaging of inpatients with bronchiolitis aiming to evaluate its utilization and possible impact on patients` management and length of hospital stay.

SUBJECTS AND METHODS

This study included 194 cases of acute bronchiolitis admitted to Al-Adan Hospital. Number of X-Rays done following admission and reasons stated in the files were recorded. Bronchiolitis severity was estimated from the data obtained.

RESULTS

Chest X-Rays were ordered in 52.1% of our inpatients with acute bronchiolitis. In nearly half of those cases, the reason for X-Ray request is a clinical severity factor, namely desaturations and apneas, and in rest of the cases, no specific reason for ordering X-Rays was documented. Significantly more patients who had two or more X-Rays were prescribed antibiotics and had statistically longer hospital stay. The number of X-Rays performed during admission was not a significant contributor to the need for PICU care, however, it was a significant factor affecting the length of hospital stay.

CONCLUSION

The implementation of acute bronchiolitis guidelines regarding imaging in admitted cases with acute bronchiolitis is highly recommended in Al-Adan hospital. Clear documentation for the reasons behind ordering X-Rays is needed for those cases. A decrease in the X-Ray utilization and subsequent unnecessary antibiotic use can help in decreasing the costs and hazards of hospitalization for patients with acute bronchiolitis.

Environmental cycles regulate development time via circadian clock mediated gating of adult emergence

BACKGROUND

Previous studies have implicated a role for circadian clocks in regulating pre-adult development of organisms. Among them two approaches are most notable: 1) use of insects whose clocks have different free-running periods and 2) imposition of artificial selection on either rate of development, timing of emergence or circadian period in laboratory populations. Using these two approaches, influence of clock on rate of development has been elucidated. However, the contribution of circadian clocks in determining time taken for pre-adult development has remained unclear. Here we present results of our studies aimed to understand this influence by examining populations of fruit flies carrying three different alleles of the period gene and hence having different free-running periods. We tried to achieve similarity of genetic background among the three strains while also ensuring that they harbored sufficient variation on loci other than period gene.

RESULTS

We find that under constant conditions, flies with long period have slower development whereas in presence of light-dark cycles (LD) of various lengths, the speed of development for each genotype is influenced by whether their eclosion rhythms can entrain to them. Under LD 12:12 (T24), where all three strains entrain, they do not show any difference in time taken for emergence, whereas under LD 10:10 (T20) where long period flies do not entrain and LD 14:14 (T28) where short period flies do not entrain, they have slower and faster pre-adult development, respectively, compared to the controls. We also show that a prior stage in development namely pupation is not rhythmic though time taken for pupation is determined by both the environmental cycle and period allele.

CONCLUSION

We discuss how in presence of daily time cues, interaction of the cyclic environmental factors with the clock determines the position and width of the gate available for a fly to emerge (duration of time within a cycle when adult emergence can occur) resulting in an altered developmental duration from that observed under constant conditions. We also discuss the relevance of genetic background influencing this regulation.

Genome-Wide Association Study of Circadian Behavior in Drosophila melanogaster

Circadian rhythms influence physiological processes from sleep–wake cycles to body temperature and are controlled by highly conserved cycling molecules. Although the mechanistic basis of the circadian clock has been known for decades, the extent to which circadian rhythms vary in nature and the underlying genetic basis for that variation is not well understood. We measured circadian period (Ʈ) and rhythmicity index in the Drosophila Genetic Reference Panel (DGRP) and observed extensive genetic variation in both. Seven DGRP lines had sexually dimorphic arrhythmicity and one line had an exceptionally long Ʈ. Genome-wide analyses identified 584 polymorphisms in 268 genes. We observed differences among transcripts for nine genes predicted to interact among themselves and canonical clock genes in the long period line and a control. Mutations/RNAi knockdown targeting these genes also affected circadian behavior. Our observations reveal that complex genetic interactions influence high levels of variation in circadian phenotypes.

The clock gene period differentially regulates sleep and memory in Drosophila

Circadian regulation is a conserved phenomenon across the animal kingdom, and its disruption can have severe behavioral and physiological consequences. Core circadian clock proteins are likewise well conserved from Drosophila to humans. While the molecular clock interactions that regulate circadian rhythms have been extensively described, additional roles for clock genes during complex behaviors are less understood. Here, we show that mutations in the clock gene period result in differential time-of-day effects on acquisition and long-term memory of aversive olfactory conditioning. Sleep is also altered in period mutants: while its overall levels don't correlate with memory, sleep plasticity in different genotypes correlates with immediate performance after training. We further describe distinct anatomical bases for Period function by manipulating Period activity in restricted brain cells and testing the effects on specific aspects of memory and sleep. In the null mutant background, different features of sleep and memory are affected when we reintroduce a form of the period gene in glia, lateral neurons, and the fan-shaped body. Our results indicate that the role of the clock gene period may be separable in specific aspects of sleep or memory; further studies into the molecular mechanisms of these processes suggest independent neural circuits and molecular cascades that mediate connections between the distinct phenomena.

Rationality for isobaric automorphic representations: the CM-case

In this note we prove a simultaneous extension of the author's joint result with M. Harris for critical values of Rankin-Selberg L-functions L ( s , Π × Π ' ) (Grobner and Harris in J Inst Math Jussieu 15:711-769, 2016, Thm. 3.9) to (i) general CM-fields F and (ii) cohomological automorphic representationsΠ ' = Π 1 ⊞ ⋯ ⊞ Π k which are the isobaric sum of unitary cuspidal automorphic representations Π i of general linear groups of arbitrary rank over F. In this sense, the main result of these notes, cf. Theorem 1.9, is a generalization, as well as a complement, of the main results in Raghuram (Forum Math 28:457-489, 2016; Int Math Res Not 2:334-372, 2010. https://doi.org/10.1093/imrn/rnp127), and Mahnkopf (J Inst Math Jussieu 4:553-637, 2005).

Addition of biomarker panel improves prediction performance of American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) calculator for cardiac risk assessment of elderly patients preparing for major non-cardiac surgery: a pilot study

BACKGROUND

Number of elderly patients subjected to extensive surgical procedures in the presence of cardiovascular morbidities is increasing every year. Therefore, there is a need to make preoperative diagnostics more accurate.

AIMS

To evaluate the usefulness of American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) calculator as a predictive tool in preoperative assessment of cardiovascular risk in elderly patients.

METHODS

This prospective pilot study included 78 patients who were being prepared for extensive non-cardiac surgeries under general anaesthesia. Their data have been processed on the interactive ACS NSQIP calculator. Blood sampling has been performed 7 days prior to surgery, and serum has been separated. Clinical, novel, and experimental biomarkers [hsCRP, H-FABP, and Survivin (BIRC5)] have been measured in specialized laboratories.

RESULTS

Mean age of included patients was 71.35 ± 6.89 years. In the case of heart complications and mortality prediction, hsCRP and ACS NSQIP showed the highest specificity and sensitivity with AUC, respectively, 0.869 and 0.813 for heart complications and 0.883 and 0.813 for mortality. When combined with individual biomarkers AUC of ACS NSQIP raised, but if we combined all three biomarkers with ACS NSQIP, AUC reached as much as 0.920 for heart complications and 0.939 for mortality.

DISCUSSION

ACS NSQIP proved to reduce inaccuracy in preoperative assessment, but it cannot be used independently, which has already been proved by other authors.

CONCLUSIONS

Our results indicate that ACS NSQIP represents an accurate tool for preoperative assessment of elderly patients, especially if combined with cardiac biomarkers.

Drosophila RSK Influences the Pace of the Circadian Clock by Negative Regulation of Protein Kinase Shaggy Activity

Endogenous molecular circadian clocks drive daily rhythmic changes at the cellular, physiological, and behavioral level for adaptation to and anticipation of environmental signals. The core molecular system consists of autoregulatory feedback loops, where clock proteins inhibit their own transcription. A complex and not fully understood interplay of regulatory proteins influences activity, localization and stability of clock proteins to set the pace of the clock. This study focuses on the molecular function of Ribosomal S6 Kinase (RSK) in the Drosophila melanogaster circadian clock. Mutations in the human rsk2 gene cause Coffin–Lowry syndrome, which is associated with severe mental disabilities. Knock-out studies with Drosophila ortholog rsk uncovered functions in synaptic processes, axonal transport and adult behavior including associative learning and circadian activity. However, the molecular targets of RSK remain elusive. Our experiments provide evidence that RSK acts in the key pace maker neurons as a negative regulator of Shaggy (SGG) kinase activity, which in turn determines timely nuclear entry of the clock proteins Period and Timeless to close the negative feedback loop. Phosphorylation of serine 9 in SGG is mediated by the C-terminal kinase domain of RSK, which is in agreement with previous genetic studies of RSK in the circadian clock but argues against the prevailing view that only the N-terminal kinase domain of RSK proteins carries the effector function. Our data provide a mechanistic explanation how RSK influences the molecular clock and imply SGG S9 phosphorylation by RSK and other kinases as a convergence point for diverse cellular and external stimuli.

Interspecific studies of circadian genes period and timeless in Drosophila

The level of rescue of clock function in genetically arrhythmic Drosophila melanogaster hosts using interspecific clock gene transformation was used to study the putative intermolecular coevolution between interacting clock proteins. Among them PER and TIM are the two important negative regulators of the circadian clock feedback loop. We transformed either the D. pseudoobscura per or tim transgenes into the corresponding arrhythmic D. melanogaster mutant (per01 or tim01) and observed >50% rhythmicity but the period of activity rhythm was either longer (D. pseudoobscura-per) or shorter than 24 h (D. pseudoobscura-tim) compared to controls. By introducing both transgenes simultaneously into double mutants, we observed that the period of the activity rhythm was rescued by the pair of hemizygous transgenes (~24 h). These flies also showed a more optimal level of temperature compensation for the period. Under LD 12:12 these flies have a D. pseudoobscura like activity profile with the absence of morning anticipation as well as a very prominent earlier evening peak of activity rhythm. These observation are consistent with the view that TIM and PER form a heterospecific coevolved module at least for the circadian period of activity rhythms. However the strength of rhythmicity was reduced by having both transgenes present, so while evidence for a coevolution between PER and TIM is observed for some characters it is not for others.

Age, period and cohort effects and the predictors of physical activity and sedentary behaviour among Chinese children, from 2004 to 2011

BACKGROUND

Very few studies have explored the effects of age, time period, and cohort in association with biological, behavioral, economic, and environmental factors predictors on physical activity (PA) and sedentary behaviour (SB) among Chinese children.

METHODS

We used data from a cohort study of the China Health and Nutrition Survey (CHNS) between 2004 and 2011 (2004, 2006, 2009 and 2011). The outcomes of interest were metabolic equivalent of task (MET) hours per week from both active and sedentary activities. Age, gender, individual characteristics, household size, asset ownership, and urbanisation were included as covariates. Age, period and cohort effects analyses for PA and SB of children (6-17 y, n = 3528) was conducted to explicitly assess differences in PA and SB due to age vs. period effects, and implicitly assess differences by cohorts due to the period-specific experiences across individuals of varying ages.

RESULTS

The mean age of the sample in each time point fluctuated from 12.6 to 11.3 years and PA slightly decreased from 50.0 ± 63.2 MET hours per week (MET-hr./wk) in 2004 to 47.1 ± 54.9 MET-hr./wk. in 2011. However, SB increased from 31.8 ± 22.0 MET-hr./wk. to 37.6 ± 22.2 MET-hr./wk. Girls had lower PA and higher SB levels than boys. Controlling for age effects, marginal period effects on PA were observed in some survey years. Higher levels of urbanisation and number of household computers served as negative and positive predictors for PA and SB, respectively. Higher household income was a positive predictor of SB. Surprisingly, bigger household size was the only negative predictor of SB (P < 0.05).

CONCLUSIONS

This longitudinal study followed a large cohort of children over a significant period of their childhood. We observed potential age and secular trends in PA levels. Higher community urbanisation and number of home computers were associated with both PA and SB levels. Larger household size was the only factor that was negatively associated with SB. These findings shed light on health policy and preventative health strategies for China and other countries that are now facing similar public health challenges.

Molecular cloning, characterization, and temporal expression of the clock genes period and timeless in the oriental river prawn Macrobrachium nipponense during female reproductive development

The circadian clock is crucial for sustaining rhythmic biochemical, physiological, and behavioral processes in living creatures. In this study, we isolated and characterized two circadian clock genes in Macrobrachium nipponense, period (Mnper) and timeless (Mntim). The complete Mnper cDNA measures 4283bp in length with an open reading frame encoding 1292 amino acids, including functional domains such as PER-ARNT-SIM (PAS), cytoplasmic localization domain (CLD), TIM interaction site (TIS), and nuclear localization signal (NLS). The deduced Mntim protein comprises1540 amino acids with functional domains such as PER interaction site (PIS), NLS, and CLD. Tissue distribution analyses showed that the two genes were highly expressed in the eyestalk and brain in both males and females, as well as being expressed in the ovary. The expression profiles of Mnper and Mntim were determined in the eyestalk, brain, and ovary under simulated breeding season and non-breeding season conditions. The expression profiles of both Mnper and Mntim appeared to be unaffected in the eyestalk. However, the expression of both genes exhibited significant seasonal variations in the brain, and thus we assumed the brain to be their functional location. The expression profiles under different simulated seasons and the variations during different ovarian stages indicate that both genes might be involved with female reproduction. Especially the mRNA levels in the brain varied greatly during these stages indicating that the clock function in the brain is closely related to ovarian development and female reproduction. And the reproductive roles of clock genes need to be elucidated.

Entrainment of eclosion and preliminary ontogeny of circadian clock gene expression in the flesh fly, Sarcophaga crassipalpis

Timing of circadian activities is controlled by rhythmic expression of clock genes in pacemaker neurons in the insect brain. Circadian behavior and clock gene expression can entrain to both thermoperiod and photoperiod but the availability of such cues, the organization of the brain, and the need for circadian behavior change dramatically during the course of insect metamorphosis. We asked whether photoperiod or thermoperiod entrains the clock during pupal and pharate adult stages by exposing flies to different combinations of thermoperiod and photoperiod and observing the effect on the timing of adult eclosion. This study used qRT-PCR to examine how entrainment and expression of circadian clock genes change during the course of development in the flesh fly, Sarcophaga crassipalpis. Thermoperiod entrains expression of period and controls the timing of adult eclosion, suggesting that the clock gene period may be upstream of the eclosion pathway. Rhythmic clock gene expression is evident in larvae, appears to cease during the early pharate adult stage, and resumes again by the time of adult eclosion. Our results indicate that both patterns of clock gene expression and the cues to which the clock entrains are dynamic and respond to different environmental signals at different developmental stages in S. crassipalpis.

Mammalian Period represses and de-represses transcription by displacing CLOCK-BMAL1 from promoters in a Cryptochrome-dependent manner

The mammalian circadian clock is based on a transcription-translation feedback loop (TTFL) consolidated by secondary loops. In the primary TTFL, the circadian locomotor output cycles kaput (CLOCK)-brain and muscle Arnt-like protein-1 (BMAL1) heterodimer acts as the transcriptional activator, and Cryptochrome (CRY) and Period (PER) proteins function as repressors. PER represses by displacing CLOCK-BMAL1 from promoters in a CRY-dependent manner. Interestingly, genes with complex promoters may either be repressed or de-repressed by PER, depending on the particular promoter regulatory elements. Here, using mouse cell lines with defined knockout mutations in clock genes, RNA-seq, ChIP-seq, and reporter gene assays coupled with measurements of DNA-protein interactions in nuclear extracts, we elucidate the dual functions of PER as repressor and de-repressor in a context-dependent manner.

The Circadian Clock Is a Key Driver of Steroid Hormone Production in Drosophila

Biological clocks allow organisms to anticipate daily environmental changes such as temperature fluctuations, abundance of daylight, and nutrient availability. Many circadian-controlled physiological states are coordinated by the release of systemically acting hormones, including steroids and insulin [1-7]. Thus, hormones relay circadian outputs to target tissues, and disrupting these endocrine rhythms impairs human health by affecting sleep patterns, energy homeostasis, and immune functions [8-10]. It is largely unclear, however, whether circadian circuits control hormone levels indirectly via central timekeeping neurons or whether peripheral endocrine clocks can modulate hormone synthesis directly. We show here that perturbing the circadian clock, specifically in the major steroid hormone-producing gland of Drosophila, the prothoracic gland (PG), unexpectedly blocks larval development due to an inability to produce sufficient steroids. This is surprising, because classic circadian null mutants are viable and result in arrhythmic adults [4, 11-14]. We found that Timeless and Period, both core components of the insect clock [15], are required for transcriptional upregulation of steroid hormone-producing enzymes. Timeless couples the circadian machinery directly to the two canonical pathways that regulate steroid synthesis in insects, insulin and PTTH signaling [16], respectively. Activating insulin signaling directly modulates Timeless function, suggesting that the local clock in the PG is normally synced with systemic insulin cues. Because both PTTH and systemic insulin signaling are themselves under circadian control, we conclude that de-synchronization of a local endocrine clock with external circadian cues is the primary cause for steroid production to fail.

Circadian clock of Drosophila montana is adapted to high variation in summer day lengths and temperatures prevailing at high latitudes

Photoperiodic regulation of the circadian rhythms in insect locomotor activity has been studied in several species, but seasonal entrainment of these rhythms is still poorly understood. We have traced the entrainment of activity rhythm of northern Drosophila montana flies in a climate chamber mimicking the photoperiods and day and night temperatures that the flies encounter in northern Finland during the summer. The experiment was started by transferring freshly emerged females into the chamber in early and late summer conditions to obtain both non-diapausing and diapausing females for the studies. The locomotor activity of the females and daily changes in the expression levels of two core circadian clock genes, timeless and period, in their heads were measured at different times of summer. The study revealed several features in fly rhythmicity that are likely to help the flies to cope with high variation in the day length and temperature typical to northern summers. First, both the non-diapausing and the diapausing females showed evening activity, which decreased towards the short day length as observed in the autumn in nature. Second, timeless and period genes showed concordant daily oscillations and seasonal shifts in their expression level in both types of females. Contrary to Drosophila melanogaster, oscillation profiles of these genes were similar to each other in all conditions, including the extremely long days in early summer and the cool temperatures in late summer, and their peak expression levels were not locked to lights-off transition in any photoperiod. Third, the diapausing females were less active than the non-diapausing ones, in spite of their younger age. Overall, the study showed that D. montana clock functions well under long day conditions, and that both the photoperiod and the daily temperature cycles are important zeitgebers for seasonal changes in the circadian rhythm of this species.

Age-period-cohort analysis of smoking prevalence among young adults in Korea

OBJECTIVES:

Smoking prevalence among Korean men in their thirties is substantially high (approximately 50%). An in-depth analysis of smoking trends among young adults in their twenties is necessary to devise antismoking policies for the next 10 years. This study aimed to identify the contributions of age, period, and birth cohort effects on smoking prevalence in young adults.

METHODS:

Subjects comprised 181,136 adults (83,947 men: 46.3%; 97,189 women: 53.7%) aged 19 to 30 years from the 2008-2013 Korea Community Health Survey. Smoking prevalence adjusted with reference to the 2008 population was applied to the age-period-cohort (APC) model to identify the independent effects of each factor.

RESULTS:

For men, smoking prevalence rapidly escalated among subjects aged 19 to 22 years and slowed down among those aged 23 to 30 years, declined during 2008 to 2010 but stabilized during 2011 to 2013, and declined in birth cohorts prior to 1988 but stabilized in subjects born after 1988. However, in APC models, smoking prevalence increased with age in the 1988 to 1991 birth cohort. In this birth cohort, smoking prevalence at age 19 to 20 years was approximately 24% but increased to 40% when the subjects turned 23 to 24 years. For women, smoking prevalence was too low to generate consistent results.

CONCLUSIONS:

Over the past six years and in recent birth cohorts, smoking prevalence in adults aged 19 to 30 years has declined and is stable. Smoking prevalence should be more closely followed as it remains susceptible to an increase depending on antismoking policies or social conditions.

Age, period and cohort effects on adult physical activity levels from 1991 to 2011 in China

BACKGROUND

To date no work has differentiated the effects of age, period, and cohort on physical activity (PA) among Chinese adults, while also considering biological, behavioral, economic, and environmental factors over time.

METHODS

We used data from the China Health and Nutrition Survey (CHNS) between 1991 and 2011 (20 years). The outcomes of interest are metabolic equivalent of task (MET) hours per week from work and domestic activities. Age, individual characteristics, household size, asset ownership, urbanization were included as covariates. Analyses for adult (≥20y) males (n = 29,343) and females (n = 31,094) was conducted to explicitly assess differences in PA due to age vs period effects, and implicitly assess differences by cohorts due to the period-specific experiences across individuals of varying ages.

RESULTS

The mean age of the sample rose from 41.31 to 50.8 years and PA decreased from 427.75 ± 264.35 MET hours per week (MET-hr/wk) in 1991 to 245.99 ± 206.65 MET-hr/wk in 2011, with much steeper declines for women compared to men. For both genders, we found non-linear decreases in PA with age over time. Controlling for age effects, negative period effects on PA were observed in each survey year, and were substantial from 1993 to 2000 for males and from 1993 to 2011 for females. The interaction between survey year and age (P < 0.05) were observed from 2004 to 2011. Higher community urbanicity, vehicle ownership, TV and computer ownership, overweight and obese, higher education served as negative predictors. Bicycle ownership, bigger household size, non-professional jobs, being married and having more children (for women) were positive predictors of PA (P < 0.05). Furthermore, at any given age, individuals who were younger at baseline had higher mean PA compared with individuals older at baseline.

CONCLUSION

This study followed a large cohort of adults over a significant portion of their lives. Strong age and secular trends were observed, resulting in an increasing number of participants who have or are likely to lower their PA levels. These trends suggest that tackling the rapid PA decline among its population is of high priority for China's public health outlook as its population ages and continues to experience significant economic and environmental changes.

The ratio of intracellular CRY proteins determines the clock period length

Although a deficiency in CRY1 or CRY2 correlates with a shorter or longer circadian period, the regulation of CRY proteins in the circadian period has not been well studied. In this study, we found that both CRY1 and CRY2 were able to rescue oscillation in CRY null cells and that they displayed different periods. Furthermore, we demonstrated that protein nuclear import rates, not protein stability, regulate the period-length at the cellular level. Co-transfection of CRY1 and CRY2 in various ratios in the same cells gives rise to the predicted period length in a dose-dependent manner. Given the distinct characteristics of the C-terminal tails of the CRY1 and CRY2 proteins, our study addresses a long-standing hypothesis that the ratio of these two CRY molecules affects the clock period.

Circadian-relevant genes are highly polymorphic in autism spectrum disorder patients

BACKGROUND

The genetic background of autism spectrum disorder (ASD) is considered a multi-genetic disorder with high heritability. Autistic children present with a higher prevalence of sleep disorders than has been observed in children with normal development. Some circadian-relevant genes have been associated with ASD (e.g., PER1, PER2, NPAS2, MTNR1A, and MTNR1B).

METHODS

We analyzed 28 ASD patients (14 with sleep disorders and 14 without) and 23 control subjects of Japanese descent. The coding regions of 18 canonical clock genes and clock-controlled genes were sequenced. Detected mutations were verified by direct sequencing analysis, and additional control individuals were screened.

RESULTS

Thirty-six base changes with amino acid changes were detected in 11 genes. Six missense changes were detected only in individuals with ASD with sleep disturbance: p.F498S in TIMELESS, p.S20R in NR1D1, p.R493C in PER3, p.H542R in CLOCK, p.L473S in ARNTL2, and p.A325V in MTNR1B. Six missense changes were detected only in individuals with ASD without sleep disturbance: p.S1241N in PER1, p.A325T in TIMELESS, p.S13T in ARNTL, p.G24E in MTNR1B, p.G24E in PER2, and p.T1177A in PER3. The p.R493C mutation in PER3 was detected in both groups. One missense change, p.P932L in PER2, was detected only in the control group. Mutations in NR1D1, CLOCK, and ARNTL2 were detected only in individuals with ASD with sleep disorder. The prevalence of the mutations detected only single time differed significantly among all ASD patients and controls (p=0.003). Two kinds of mutations detected only in individuals with ASD with sleep disorder, p.F498S in TIMELESS and p.R366Q in PER3, were considered to affect gene function by three different methods: PolyPhen-2, scale-invariant feature transform (SIFT) prediction, and Mutation Taster (www.mutationtaster.org). The mutations p.S20R in NR1D1, p.H542R in CLOCK, p.L473S in ARNTL2, p.A325T in TIMELESS, p.S13T in ARNTL, and p.G24E in PER2 were diagnosed to negatively affect gene function by more than one of these methods.

CONCLUSION

Mutations in circadian-relevant genes affecting gene function are more frequent in patients with ASD than in controls. Circadian-relevant genes may be involved in the psychopathology of ASD.

Circadian rhythms of clock gene expression in the cerebellum of serotonin-deficient Pet-1 knockout mice

Serotonin plays an important role in the central regulation of circadian clock function. Serotonin levels are generally higher in the brain during periods of high activity, and these periods are in turn heavily regulated by the circadian clock located in the suprachiasmatic nucleus. However, the role of serotonin as a regulator of circadian rhythms elsewhere in the brain has not been extensively examined. In this study, we examined circadian rhythms of clock gene expression in the cerebellum in mice lacking the Pet-1 transcription factor, which results in a developed brain that is deficient in serotonin neurons. If serotonin helps to synchronize rhythms in brain regions other than the suprachiasmatic nucleus, we would expect to see differences in clock gene expression in these serotonin deficient mice. We found minor differences in the expression of Per1 and Per2 in the knockout mice as compared to wild type, but these differences were small and of questionable functional importance. We also measured the response of cerebellar clocks to injections of the serotonin agonist 8-OH-DPAT during the early part of the night. No effect on clock genes was observed, though the immediate-early gene Fos showed increased expression in wild type mice but not the knockouts. These results suggest that serotonin is not an important mediator of circadian rhythms in the cerebellum in a way that parallels its regulation of the circadian clock in the suprachiasmatic nucleus.

Do circadian genes and ambient temperature affect substrate-borne signalling during Drosophila courtship?

Courtship vibratory signals can be air-borne or substrate-borne. They convey distinct and species-specific information from one individual to its prospective partner. Here, we study the substrate-borne vibratory signals generated by the abdominal quivers of the Drosophila male during courtship; these vibrations travel through the ground towards courted females and coincide with female immobility. It is not known which physical parameters of the vibrations encode the information that is received by the females and induces them to pause. We examined the intervals between each vibratory pulse, a feature that was reported to carry information for animal communication. We were unable to find evidence of periodic variations in the lengths of these intervals, as has been reported for fly acoustical signals. Because it was suggested that the genes involved in the circadian clock may also regulate shorter rhythms, we search for effects of period on the interval lengths. Males that are mutant for the period gene produced vibrations with significantly altered interpulse intervals; also, treating wild type males with constant light results in similar alterations to the interpulse intervals. Our results suggest that both the clock and light/dark cycles have input into the interpulse intervals of these vibrations. We wondered if we could alter the interpulse intervals by other means, and found that ambient temperature also had a strong effect. However, behavioural analysis suggests that only extreme ambient temperatures can affect the strong correlation between female immobility and substrate-borne vibrations.

The liver of goldfish as a component of the circadian system: Integrating a network of signals

The circadian system drives daily physiological and behavioral rhythms that allow animals to anticipate cyclic environmental changes. The discovery of the known as "clock genes", which are very well conserved through vertebrate phylogeny, highlighted the molecular mechanism of circadian oscillators functioning, based on transcription and translation cycles (∼ 24 h) of such clock genes. Studies in goldfish have shown that the circadian system in this species is formed by a net of oscillators distributed at central and peripheral locations, as the retina, brain, gut and liver, among others. In this work we review the existing information about the hepatic oscillator in goldfish due to its relevance in metabolism, and its key role as target of a variety of humoral signals. Different input signals modify the molecular clockwork in the liver of goldfish. Among them, there are environmental cues (photocycle and feeding regime) and different encephalic and peripheral endogenous signals (orexin, ghrelin and glucocorticoids). Per clock genes seem to be a common target for different signals. Thus, this genes family might be important for shifting the hepatic oscillator. The physiological relevance of the crosstalking between metabolic and feeding-related hormones and the hepatic clock sets the stage for the hypothesis that these hormones could act as "internal zeitgebers" communicating oscillators in the goldfish circadian system.

Alcohol and lithium have opposing effects on the period and phase of the behavioral free-running activity rhythm

Bipolar patients have a high prevalence of comorbid alcohol use and abuse disorders, while chronic alcohol drinking may increase the presence and severity of certain symptoms of bipolar disorder. As such, there may be many individuals that are prescribed lithium to alleviate the manic symptoms of bipolar disorder, but also drink alcohol concurrently. In addition, both alcoholics and individuals with bipolar disorder often exhibit disruptions to their sleep-wake cycles and other circadian rhythms. Interestingly, both ethanol and lithium are known to alter both the period and the phase of free-running rhythms in mammals. While lithium is known to lengthen the period, ethanol seems to shorten the period and attenuate the responses to acute light pulses. Therefore, the present study aimed to determine whether ethanol and lithium have opposing effects on the circadian pacemaker when administered together. C57BL/6J mice were provided drinking solutions containing lithium, alcohol, or both, and their free-running rhythms along with their response to photic phase shifts were investigated. Mice treated with lithium displayed period lengthening, which was almost completely negated when ethanol was added. Moreover, ethanol significantly attenuated light-induced phase delays while the addition of lithium partially restored this response. These results indicate that alcohol and lithium have opposing effects on behavioral circadian rhythms. Individuals with bipolar disorder who are prescribed lithium and who drink alcohol might be inadvertently altering their sleep and circadian cycles, which may exacerbate their symptoms.

The hepatic circadian clock modulates xenobiotic metabolism in mice

The circadian clock generates daily cycles of gene expression that regulate physiological processes. The liver plays an important role in xenobiotic metabolism and also has been shown to possess its own cell-based clock. The liver clock is synchronized by the master clock in the brain, and a portion of rhythmic gene expression can be driven by behavior of the organism as a whole even when the hepatic clock is suppressed. So far, however, there is relatively little evidence indicating whether the liver clock is functionally important in modulating xenobiotic metabolism. Thus, mice lacking circadian clock function in the whole body or specifically in liver were challenged with pentobarbital and acetaminophen, and pentobarbital sleep time (PBST) and acetaminophen toxicity, respectively, was assessed at different times of day in mutant and control mice. The results suggest that the liver clock is essential for rhythmic changes in xenobiotic detoxification. Surprisingly, it seems that the way in which the clock is disrupted determines the rate of xenobiotic metabolism in the liver. CLOCK-deficient mice are remarkably resistant to acetaminophen and exhibit a longer PBST, while PERIOD-deficient mice have a short PBST. These results indicate an essential role of the tissue-intrinsic peripheral circadian oscillator in the liver in regulating xenobiotic metabolism.

Period homolog LIN-42 regulates miRNA transcription to impact developmental timing

Two recent studies by Van Wynsberghe et al. and Perales et al. in the nematode C. elegans have demonstrated a new function of the Period protein homolog LIN-42 in negatively regulating microRNA (miRNA) biogenesis at the transcriptional level. LIN-42 is a complex gene with 4 isoforms and multiple functions including the regulation of molting, developmental timing and entry into dauer. These recent studies uncover an additional function of LIN-42 as a negative regulator of miRNA transcription. Approximately 95% of miRNAs present in eggs and 33% of miRNAs present in L4 stage worms were upregulated in lin-42 mutant worms relative to wild type (WT) worms, suggesting that LIN-42 globally regulates miRNA biogenesis. Expression from both a let-7 miRNA and a lin-4 miRNA transcriptional reporter were enhanced in the absence of lin-42. Additionally, chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq) of late larval stage worms showed that LIN-42 bound the let-7 promoter, suggesting that LIN-42 affects mature miRNA levels by inhibiting their transcription. In addition to miRNAs, LIN-42 also predominantly bound to the promoters of many diverse protein-coding genes. These findings support the action of LIN-42 at multiple points within the heterochronic and other regulatory pathways to impact a multitude of functions including developmental timing.

Effects of lighting condition on circadian behavior in 5-HT1A receptor knockout mice

Serotonin (5-HT) is an important regulator of the mammalian circadian system, and has been implicated in modulating entrained and free-running rhythms, as well as photic and non-photic phase shifting. In general, 5-HT appears to oppose the actions of light on the circadian system of nocturnal rodents. As well, 5-HT mediates, at least in part, some non-photic responses. The 5-HT1A, 1B and 7 receptors regulate these acute responses to zeitgebers. 5-HT also regulates some entrained and free-running properties of the circadian clock. The receptors that contribute to these phenomena have not been fully examined. Here, we use 5-HT1A receptor knockout (KO) mice to examine the response of the mouse circadian system to a variety of lighting conditions, including a normal light-dark cycle (LD), T-cycles, phase advanced LD cycles, constant darkness (DD), constant light (LL) and a 6 hour dark pulse starting at CT5. Relative to wildtype mice, the 5-HT1A receptor KO mice have lower levels of activity during the first 8h of the night/subjective night in LD and LL, later activity onsets on transient days during re-entrainment, shorter free-running periods in LL when housed with wheels, and smaller phase shifts to dark pulses. No differences were noted in activity levels during DD, alpha under any light condition, free-running period in DD, or phase angle of entrainment in LD. While the 5-HT1A receptor plays an important role in regulating photic and non-photic phase shifting, its contribution to entrained and free-running properties of the circadian clock is relatively minor.

Dual modes of CLOCK:BMAL1 inhibition mediated by Cryptochrome and Period proteins in the mammalian circadian clock

The mammalian circadian clock is based on a transcription–translation feedback loop in which CLOCK and BMAL1 proteins act as transcriptional activators of Cryptochrome and Period genes, which encode proteins that repress CLOCK–BMAL1 with a periodicity of ∼ 24 h. Ye et al. show that CRY binds to CLOCK–BMAL1 at the promoter and inhibits CLOCK–BMAL1-dependent transcription without dissociating the complex. PER alone has no effect on CLOCK–BMAL1-activated transcription, but in the presence of CRY, nuclear entry of PER inhibits transcription by displacing CLOCK–BMAL1 from the promoter.

The mammalian circadian clock is based on a transcription–translation feedback loop (TTFL) in which CLOCK and BMAL1 proteins act as transcriptional activators of Cryptochrome and Period genes, which encode proteins that repress CLOCK–BMAL1 with a periodicity of ∼24 h. In this model, the mechanistic roles of CRY and PER are unclear. Here, we used a controlled targeting system to introduce CRY1 or PER2 into the nuclei of mouse cells with defined circadian genotypes to characterize the functions of CRY and PER. Our data show that CRY is the primary repressor in the TTFL: It binds to CLOCK–BMAL1 at the promoter and inhibits CLOCK–BMAL1-dependent transcription without dissociating the complex (“blocking”-type repression). PER alone has no effect on CLOCK–BMAL1-activated transcription. However, in the presence of CRY, nuclear entry of PER inhibits transcription by displacing CLOCK–BMAL1 from the promoter (“displacement”-type repression). In light of these findings, we propose a new model for the mammalian circadian clock in which the negative arm of the TTFL proceeds by two different mechanisms during the circadian cycle.

Time-place learning and memory persist in mice lacking functional Per1 and Per2 clock genes

With time-place learning, animals link a stimulus with the location and the time of day. This ability may optimize resource localization and predator avoidance in daily changing environments. Time-place learning is a suitable task to study the interaction of the circadian system and memory. Previously, we showed that time-place learning in mice depends on the circadian system and Cry1 and/or Cry2 clock genes. We questioned whether time-place learning is Cry specific or also depends on other core molecular clock genes. Here, we show that Per1/Per2 double mutant mice, despite their arrhythmic phenotype, acquire time-place learning similar to wild-type mice. As well as an established role in circadian rhythms, Per genes have also been implicated in the formation and storage of memory. We found no deficiencies in short-term spatial working memory in Per mutant mice compared to wild-type mice. Moreover, both Per mutant and wild-type mice showed similar long-term memory for contextual features of a paradigm (a mild foot shock), measured in trained mice after a 2-month nontesting interval. In contrast, time-place associations were lost in both wild-type and mutant mice after these 2 months, suggesting a lack of maintained long-term memory storage for this type of information. Taken together, Cry-dependent time-place learning does not require Per genes, and Per mutant mice showed no PER-specific short-term or long-term memory deficiencies. These results limit the functional role of Per clock genes in the circadian regulation of time-place learning and memory.

Perioperative hypoxemia is common with horizontal positioning during general anesthesia and is associated with major adverse outcomes: a retrospective study of consecutive patients

Background

Reported perioperative pulmonary aspiration (POPA) rates have substantial variation. Perioperative hypoxemia (POH), a manifestation of POPA, has been infrequently studied beyond the PACU, for patients undergoing a diverse array of surgical procedures.

Methods

Consecutive adult patients with ASA I-IV and pre-operative pulmonary stability who underwent a surgical procedure requiring general anesthesia were investigated. Using pulse oximetry, POH was documented in the operating room and during the 48 hours following PACU discharge. POPA was the presence of an acute pulmonary infiltrate with POH.

Results

The 500 consecutive, eligible patients had operative body-positions of prone 13%, decubitus 8%, sitting 1%, and supine/lithotomy 78%, with standard practice of horizontal recumbency. POH was found in 150 (30%) patients. Post-operative stay with POH was 3.7 ± 4.7 days and without POH was 1.7 ± 2.3 days (p < 0.0001). POH rate varied from 14% to 58% among 11 of 12 operative procedure-categories. Conditions independently associated with POH (p < 0.05) were acute trauma, BMI, ASA level, glycopyrrolate administration, and duration of surgery. POPA occurred in 24 (4.8%) patients with higher mortality (8.3%), when compared to no POPA (0.2%; p = 0.0065). Post-operative stay was greater with POPA (7.7 ± 5.7 days), when compared to no POPA (2.0 ± 2.9 days; p = 0.0001). Conditions independently associated with POPA (p < 0.05) were cranial procedure, ASA level, and duration of surgery. POPA, acute trauma, duration of surgery, and inability to extubate in the OR were independently associated with post-operative stay (p < 0.05). POH, gastric dysmotility, acute trauma, cranial procedure, emergency procedure, and duration of surgery had independent correlations with post-operative length of stay (p < 0.05).

Conclusions

Adult surgical patients undergoing general anesthesia with horizontal recumbency have substantial POH and POPA rates. Hospital mortality was greater with POPA and post-operative stay was increased for POH and POPA. POH rates were noteworthy for virtually all categories of operative procedures and POH and POPA were independent predictors of post-operative length of stay. A study is needed to determine if modest reverse-Trendelenburg positioning during general anesthesia has a relationship with reduced POH and POPA rates.

elegans

MicroRNAs (miRNAs) are small RNAs that post-transcriptionally regulate gene expression in many multicellular organisms. They are encoded in the genome and transcribed into primary (pri-) miRNAs before two processing steps that ultimately produce the mature miRNA. In order to generate the appropriate amount of a particular miRNA in the correct location at the correct time, proper regulation of miRNA biogenesis is essential. Here we identify the Period protein homolog LIN-42 as a new regulator of miRNA biogenesis in Caenorhabditis elegans. We mapped a spontaneous suppressor of the normally lethal let-7(n2853) allele to the lin-42 gene. Mutations in this allele (ap201) or a second lin-42 allele (n1089) caused increased mature let-7 miRNA levels at most time points when mature let-7 miRNA is normally expressed. Levels of pri-let-7 and a let-7 transcriptional reporter were also increased in lin-42(n1089) worms. These results indicate that LIN-42 normally represses pri-let-7 transcription and thus the accumulation of let-7 miRNA. This inhibition is not specific to let-7, as pri- and mature levels of lin-4 and miR-35 were also increased in lin-42 mutants. Furthermore, small RNA-seq analysis showed widespread increases in the levels of mature miRNAs in lin-42 mutants. Thus, we propose that the period protein homolog LIN-42 is a global regulator of miRNA biogenesis.

Impacts of moonlight on fish reproduction

The waxing and waning cycle of the moon is repeated at approximately 1-month intervals, and concomitant changes occur in the levels of moonlight and cueing signals detected by organisms on the earth. In the goldlined spinefoot Siganus guttatus, a spawner lunar-synchronized around the first quarter moon, periodic changes in moonlight are used to cue gonadal development and gamete release. Rearing of mature fish under artificial constant full moon and new moon conditions during the spawning season leads to disruption or delay of synchronous spawning around the predicted moon phase. Melatonin, an endogenous transducer of the environmental light/dark cycle, increases in the blood and in the pineal gland around the new moon period and decreases around the full moon period. In synchrony with melatonin fluctuation, melatonin receptor(s) mRNA abundance is higher during the new moon period than during the full moon. The melatonin/melatonin receptor system is likely affected by moonlight. Measurements of the expression patterns of clock genes in neural tissues demonstrate that Cryptochrome (Cry1 and Cry3) and Period (Per2) fluctuate with lunar periodicity, the former peaking in the medial part of the brain around the first quarter moon period, and the latter peaking in the pineal gland around the full moon. Some clock genes may respond to periodic changes in moon phase and appear to be involved in the generation of lunar-related rhythmicity in lunar spawners. Thus, some fish use moonlight-related periodicities as reliable information for synchronizing the timing of reproductive events.