Association between light exposure at night and manic symptoms in bipolar disorder: cross-sectional analysis of the APPLE cohort

ABSTRACT

Previous studies have found that keeping the room dark at night was associated with a decrease in manic symptoms for patients with bipolar disorder (BD). However, the association between light at night of real-life conditions and manic symptoms is unclear. We investigated the association between bedroom light exposure at night and manic symptoms in BD patients. One-hundred and eighty-four outpatients with BD participated in this cross-sectional study. The average light intensity at night during sleep was evaluated using a portable photometer for seven consecutive nights. Manic symptoms were assessed using the Young Mania Rating Scale (YMRS), and scores ≥5 were treated as a “hypomanic state.” The median (interquartile range) YMRS score was 2.0 (0–5.0), and 52 (28.2%) participants were in a hypomanic state. The prevalence of a hypomanic state was significantly higher in the participants with an average light intensity at night exposure of ≥3 lux than in those with <3 lux (36.7% versus 21.9%; P = .02). In multivariable logistic regression analysis adjusted for BD type, depressive symptoms, sleep duration, and daytime physical activity, the odds ratio (OR) for a hypomanic state was significantly higher for the participants with an average light intensity at night exposure of ≥3 lux than for those with <3 lux (OR: 2.15, 95% confidence interval: 1.09–4.22, P = .02). This association remained significant at the cutoff value of YMRS score ≥6 (OR: 2.51, 95% confidence interval: 1.15–5.46; P = .02). The findings of this study indicate bedroom light exposure at night is significantly associated with manic symptoms in BD patients. Although the results of this cross-sectional investigation do not necessarily imply causality, they may serve to inform beneficial nonpharmacological intervention and personalized treatment of BD patients.     

Potential for Powered Flight Neared by Most Close Avialan Relatives,but Few Crossed Its Thresholds

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Early development and neurogenesis of Temnopleurus reevesii

Sea urchins are model non‐chordate deuterostomes, and studying the nervous system of their embryos can aid in the understanding of the universal mechanisms of neurogenesis. However, despite the long history of sea urchin embryology research, the molecular mechanisms of their neurogenesis have not been well investigated, in part because neurons appear relatively late during embryogenesis. In this study, we used the species Temnopleurus reevesii as a new sea urchin model and investigated the detail of its development and neurogenesis during early embryogenesis. We found that the embryos of T. reevesii were tolerant of high temperatures and could be cultured successfully at 15–30°C during early embryogenesis. At 30°C, the embryos developed rapidly enough that the neurons appeared at just after 24 h. This is faster than the development of other model urchins, such as Hemicentrotus pulcherrimus or Strongylocentrotus purpuratus. In addition, the body of the embryo was highly transparent, allowing the details of the neural network to be easily captured by ordinary epifluorescent and confocal microscopy without any additional treatments. Because of its rapid development and high transparency during embryogenesis, T. reevesii may be a suitable sea urchin model for studying neurogenesis. Moreover, the males and females are easily distinguishable, and the style of early cleavages is intriguingly unusual, suggesting that this sea urchin might be a good candidate for addressing not only neurology but also cell and developmental biology.     

Discovery of pyrazolo[3,4-d]pyrimidine derivatives as GPR119 agonists

We designed and synthesized a novel series of phenylamino- and phenoxy-substituted pyrazolo[3,4-d]pyrimidine derivatives as GPR119 agonists. SAR studies indicated that electron-withdrawing substituents on the phenyl ring are important for potency and full efficacy. Compound 26 combined good potency with a promising pharmacokinetic profile in mice, and lowered the glucose excursion in mice in an oral glucose-tolerance test.     

Temporal,cell-specific,and tissue-preferential expression of myrosinase genes during embryo and seedling development in Sinapis alba

The expression of the genes for two types of myrosinase (EC 3.2.3.1), designated MA and MB, during embryo and seedling development was investigated in Sinapis alba L. by in-situ and RNA slot-blot analyses. The expression of MA and MB genes followed similar temporal profiles during embryogenesis, but MB mRNA was present in considerably higher amounts than MA mRNA. In the embryo, both MA and MB genes are activated in cotyledons and axis. The MB genes are preferentially expressed in the cotyledons whereas MA genes are preferentially expressed in the axis. In the developing seedling, MA mRNA was not present in the organs investigated. By contrast, MB mRNA was found in appreciable amounts in hypocotyls, cotyledons and developing leaves. The MB genes seem to be activated preferentially in tissues undergoing rapid cell division and — or cell expansion.Abbreviations DAP days after pollination - MA, MB A type, B type myrosinases in Sinapis alba Anna-Stina Höglund (Uppsala Genetic Center) is gratefully acknowledged for valuable discussion, Anders Gobl (Department of Immunology, Uppsala University) for kindly advice with the labeling of probes and Qingzhu Zhai (Department of Pharmaceutical Biosciences, Uppsala University) for help with seed harvest. This work was supported by grants from the Swedish Research Council for Forestry and Agriculture.     

Salinity tolerance of three ostracode species (Crustacea:Ostracoda) of Iberian saline lakes

Laboratory experiments and field data were used to determine salinity tolerance limits of three ostracode species (Prionocypris aragonica, Eucypris mareotica and Heterocypris barbara) from Iberian saline lakes. Salinity tolerance appeared related to ionic composition and temperature. Implications for ostracode ecology and geographical distribution are evaluated.     

Influence of Methanogenic Populations in Holocene Lacustrine Sediments Revealed by Clone Libraries and Fatty Acid Biogeochemistry

Methanogenic populations were investigated in subsaline Laguna Potrok Aike sediments, southern Argentina. Microbial density and activity were assessed via cell count and in situ ATP detection for the last ～11K years. Methanogen phylogenetics highlighted species stratification throughout depth, whereas CO₂ reduction was the major pathway leading to methane production. Organic substrates, characterized using pore water analysis, bulk organic fractions and saturated fatty acids, showed a clear link between sediment colonization and initial organic sources. Concentrations and δ¹³C compositions of methane and fatty acids provided final evidence of a microbial imprint on Holocene organic proxies in the most colonized intervals.     

Lability of fat stores in peripubertal wild house mice

Summary Traditionally, the adaptive value of mammalian white fat stores is considered in relation to longterm needs such as providing protection against the vagaries of winter or signalling the reproductive system when energy reserves are sufficient to risk pregnancy. As shown here, the fat stores of young house mice could not serve such needs. Despite prolonged acclimation and excess nesting material, food deprivation at 10°C significantly lowered the fat stores of peripubertal female house mice in only 12 h, and would exhaust them in 30 h. Even close to thermoneutrality (24°C) the calculated time to exhaustion was only 70 h. The fat stores of a young house mouse are obviously too meager to offer any meaningful protection over a winter of several months duration, or even over a 5–6-week cycle of pregnancy and lactation. Furthermore, in a wild habitat where food availability and ambient temperature can vary rapidly and greatly, such fat stores would be too labile to effectively coordinate puberty with somatic development.