Sleep problems and daytime sleepiness in children with ADHD: Associations with social, emotional, and behavioral functioning at school, a cross-sectional study.

Background: Sleep problems and daytime sleepiness are common in children with attention-deficit hyperactivity disorder (ADHD) and are associated with poor parent-reported functional outcomes. However, the potential impact of sleep problems or daytime sleepiness on the school functioning of children with ADHD remains unknown. We aimed to determine if sleep problems and daytime sleepiness were associated with the social, emotional, and behavioral school-based functioning of children with ADHD and comorbid sleep problems. Methods: Children aged 5-13 years with ADHD and a moderate-severe sleep problem (confirmed using American Academy of Sleep Medicine diagnostic criteria) were recruited from 43 pediatric practices across Victoria and Queensland, Australia (N = 257). Parent-rated sleep problems were assessed using the Children's Sleep Habits Questionnaire (CSHQ) and teacher-rated daytime sleepiness using the Teacher's Daytime Sleepiness Questionnaire. Teacher-rated social, emotional, and behavioral school functioning was assessed using three scales (peer problems, emotional problems, and conduct problems) from the Strength and Difficulties Questionnaire. Data was analyzed using Pearson correlations and linear regression models. Results: Teacher-rated daytime sleepiness was associated with higher levels of emotional (ß = 0.39; 95% CI = 0.25-0.52) and behavioral problems (ß = 0.47; CI = 0.36-0.58) in adjusted models. While total sleep duration and parent-rated sleep problems were not associated with daytime sleepiness or school functioning, the CSHQ subscale night wakings was correlated with teacher-rated daytime sleepiness (r = 0.21; p < 0.01). Conclusions: Daytime sleepiness (possibly as an indicator of sleep quality) may be a better predictor of school functioning in children with ADHD who have concomitant sleep problems than total sleep duration or parent-rated sleep problems.

Women's experiences of polycystic ovary syndrome diagnosis.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common and complex endocrine condition affecting women across the lifespan. Diagnosis experience may impact on physical and emotional well-being and engagement with evidence-based management and treatment. OBJECTIVE: To explore the perceived experience of PCOS diagnosis, prior to development of an evidence-based guideline for PCOS assessment and management. METHODS: Cross-sectional study, involving devised questionnaires completed by a national, community-based sample of 210 women with a previous medical diagnosis of PCOS, aged 18-45 years, in Australia. Main outcome measures included time to diagnosis, number of health professionals seen and information provision. RESULTS: Mean age (± standard deviation) was 31 (±5.8) years and median body mass index (interquartile range) was 30 (12) kg/m(2). For 24% of women, PCOS diagnosis took >2 years and 39% saw three or more health professionals before diagnosis was made. The majority (60%) reported they were not given or referred to information sources at time of diagnosis, 20% reported receiving information and 20% were given information but felt it was inadequate. Of those who reported provision of information at diagnosis, 62% felt dissatisfied with or indifferent to information provided about PCOS, 79% reported being provided with information about lifestyle management, 89% reported being provided with information about medical therapy, 83% about long-term complications and 95% about potential infertility. CONCLUSIONS: PCOS diagnosis experience can be lengthy, involve many health professionals and leave unmet information needs. The current findings inform the need for evidence-based PCOS resources for women and health professionals.

Pre-replication complex proteins assemble at regions of low nucleosome occupancy within the Chinese hamster dihydrofolate reductase initiation zone.

Genome-scale mapping of pre-replication complex proteins has not been reported in mammalian cells. Poor enrichment of these proteins at specific sites may be due to dispersed binding, poor epitope availability or cell cycle stage-specific binding. Here, we have mapped sites of biotin-tagged ORC and MCM protein binding in G1-synchronized populations of Chinese hamster cells harboring amplified copies of the dihydrofolate reductase (DHFR) locus, using avidin-affinity purification of biotinylated chromatin followed by high-density microarray analysis across the DHFR locus. We have identified several sites of significant enrichment for both complexes distributed throughout the previously identified initiation zone. Analysis of the frequency of initiations across stretched DNA fibers from the DHFR locus confirmed a broad zone of de-localized initiation activity surrounding the sites of ORC and MCM enrichment. Mapping positions of mononucleosomal DNA empirically and computing nucleosome-positioning information in silico revealed that ORC and MCM map to regions of low measured and predicted nucleosome occupancy. Our results demonstrate that specific sites of ORC and MCM enrichment can be detected within a mammalian initiation zone, and suggest that initiation zones may be regions of generally low nucleosome occupancy where flexible nucleosome positioning permits flexible pre-RC assembly sites.

Impaired replication dynamics at the FRA3B common fragile site.

Chromosomal common fragile sites (CFSs) are genetically unstable regions of the genome that are induced by conditions that impair DNA replication. In this report, we show that treatment with the DNA polymerase inhibitor, aphidicolin (APH), slows the replication rate throughout S phase. To investigate the unusual sensitivity of CFSs to APH-induced replication stress, we examined replication dynamics within a 50 kb region of the most frequently expressed CFS, FRA3B. We mapped four origins of replication, ori 1-4, using two independent methods. In untreated cells, we detected significantly less newly replicated DNA at FRA3B ori 1-3, as compared with three control origins located within non-fragile regions (NCFSs). In APH-treated cells, all FRA3B and control origins tested were active; however, there was a significant increase of nascent strand DNA at the control origins and, to a lesser extent, at the FRA3B ori 1-3. On the basis of these observations and the theoretical modeling of the nascent strand abundance assay developed in this study, we hypothesize that CFS origins may be less efficient, and that APH treatment slows replication fork movement near these origins to a greater extent, resulting in impaired DNA replication and, ultimately, leading to the genetic instability characteristic of CFSs.

Common fragile sites are characterized by histone hypoacetylation.

Common fragile sites (CFSs) represent large, highly unstable regions of the human genome. CFS sequences are sensitive to perturbation of replication; however, the molecular basis for the instability at CFSs is poorly understood. We hypothesized that a unique epigenetic pattern may underlie the unusual sensitivity of CFSs to replication interference. To examine this hypothesis, we analyzed chromatin modification patterns within the six human CFSs with the highest levels of breakage, and their surrounding non-fragile regions (NCFSs). Chromatin at most of the CFSs analyzed has significantly less histone acetylation than that of their surrounding NCFSs. Trichostatin A and/or 5-azadeoxycytidine treatment reduced chromosome breakage at CFSs. Furthermore, chromatin at the most commonly expressed CFS, the FRA3B, is more resistant to micrococcal nuclease than that of the flanking non-fragile sequences. These results demonstrate that histone hypoacetylation is a characteristic epigenetic pattern of CFSs, and chromatin within CFSs might be relatively more compact than that of the NCFSs, indicating a role for chromatin conformation in genomic instability at CFSs. Moreover, lack of histone acetylation at CFSs may contribute to the defective response to replication stress characteristic of CFSs, leading to the genetic instability characteristic of this regions.

Gestational diabetes is associated with postpartum hemorrhage in Indigenous Australian women in the PANDORA study: A prospective cohort.

OBJECTIVE: To assess associations of hyperglycemia in pregnancy with the risk of postpartum hemorrhage (PPH) in a prospective cohort of Indigenous and non-Indigenous women, compared with normoglycemia. METHODS: Data were from 1102 (48% Indigenous) women of the Pregnancy And Neonatal Diabetes Outcomes in Remote Australia (PANDORA) Study. Age-adjusted associations of gestational diabetes mellitus (GDM) or pre-existing type 2 diabetes mellitus (T2DM), obstetric and demographic covariables with PPH (blood loss ≥500 ml) were assessed using logistic regression. Multivariable-adjusted models included Indigenous ethnicity, diabetes type and their interaction. RESULTS: A higher proportion of Indigenous women developed PPH than non-Indigenous women (32% versus 22%; P < 0.001). Compared with non-Indigenous women with normoglycemia, risks of PPH for Indigenous women with GDM or T2DM were higher (odds ratio [OR] 1.83, 95% confidence intervals [CI] 1.11-3.02, and OR 1.72, 95% CI 0.99-3.00 after age adjustment, OR 1.84, 95% CI 1.06-3.19, and OR 1.33, 95% CI 0.70-2.54 after adjustment for school education and delivery mode, and OR 1.62, 95% CI 0.95-2.77, and OR 0.99, 95% CI 0.53-1.86 after adjustment for birth weight). Importantly, Indigenous women without hyperglycemia in pregnancy were not at increased risk of PPH. CONCLUSION: The significantly higher rates of PPH experienced by Indigenous women compared with non-Indigenous women may be explained by a greater effect of GDM among Indigenous women that was only partly accounted for by birth weight.

Definition of network types - Prediction of dough mechanical behaviour under shear by gluten microstructure.

This study defines network types of wheat gluten to describe spatial arrangements of gluten networks in relation to dough mechanical behaviour. To achieve a high variety in gluten arrangements, ten specific and unspecific gluten-modifying agents in increasing concentrations were added to wheat dough. Gluten microstructure was visualized by confocal laser scanning microscopy and quantified by protein network analysis. Dough rheological behaviour was determined by both oscillatory and creep-recovery tests. Based on correlation matrices and principal component analysis, six different network types were identified and associated to their rheological characteristics: a cleaved (low viscous), rigid (highly viscous), spread (viscoelastic), strengthened (viscoelastic), particulate and dense (highly viscous) or particulate and loose (low viscous) network. Furthermore, rheological dough properties of specifically gluten-modified samples were predicted with five microstructural gluten attributes (lacunarity, branching rate, end-point rate, protein width, average protein length) and assigned properly by the obtained partial least square model with an accuracy up to 90% (e.g., R2Y = 0.84 for G*, 0.85 for tanδ, 0.90 for Jmax). As a result, rheological properties of wheat doughs were predicted from microstructural investigations. This novel, quantitative definition of the relation between structure and mechanical behaviour can be used for developments of new wheat products with targeted properties.

Gluten Polymer Networks-A Microstructural Classification in Complex Systems.

A classification of gluten polymer networks would support a better understanding of structure-function relationships of any gluten polymer material and thus, the control of processing properties. However, quantification and interpretation of the gluten network structures is challenging due to their complexity. Thus, the network formation was altered by specific gluten-modifying agents (glutathione, ascorbic acid, potassium bromate, glucose oxidase, transglutaminase, bromelain) in this study in order to clarify if structural alterations can be detected on a microstructural level and to specify different polymer arrangements in general. Microstructure analysis was performed by confocal laser scanning microscopy followed by quantification with protein network analysis. It was shown that alterations in gluten microstructure could be elucidated according to the kind of modification in cross-linking (disulphide, (iso) peptide, dityrosyl). Linear correlations of structural network attributes among each other were found, leading to an assertion in general: the higher the branching rate, the thinner the protein threads and the larger the interconnected protein aggregate. Considering the morphological attribute lacunarity, a quantitative classification of different gluten arrangements was established. These assertions were extended by using unspecific gluten-modifying agents in addition to the specific ones. Ultimately, five network types were proposed based on diverse polymer arrangements.

The essence of replication timing: determinants and significance.

In eukaryotic organisms, chromosomal DNA replication initiates at multiple sites on the chromosome at different times, following a temporal replication program. Though it is intriguing that all eukaryotic cells possess a temporal replication program that is conserved from one cell cycle to the next, it is not known whether this program is essential for the replication process per se, what specifies the temporal replication program, or whether there is a causal relationship between replication timing and other nuclear processes such as transcription. Emerging studies suggest that replication timing may indeed precede and dictate other cellular processes involving chromatin. Moreover, a systematic correlation between altered replication timing and cancer development has been observed. These studies suggest that replication timing may be an important feature of genome organization with vital functional significance.

High-throughput mapping of origins of replication in human cells.

Mapping origins of replication has been challenging in higher eukaryotes. We have developed a rapid, genome-wide method to map origins of replication in asynchronous human cells by combining the nascent strand abundance assay with a highly tiled microarray platform, and we validated the technique by two independent assays. We applied this method to analyse the enrichment of nascent DNA in three 50-kb regions containing known origins of replication in the MYC, lamin B2 (LMNB2) and haemoglobin beta (HBB) genes, a 200-kb region containing the rare fragile site, FRAXA, and a 1,075-kb region on chromosome 22; we detected most of the known origins and also 28 new origins. Surprisingly, the 28 new origins were small in size and located predominantly within genes. Our study also showed a strong correlation between origin replication timing and chromatin acetylation.

Histone acetylation regulates the time of replication origin firing.

The temporal firing of replication origins throughout S phase in yeast depends on unknown determinants within the adjacent chromosomal environment. We demonstrate here that the state of histone acetylation of surrounding chromatin is an important regulator of temporal firing. Deletion of RPD3 histone deacetylase causes earlier origin firing and concurrent binding of the replication factor Cdc45p to origins. In addition, increased acetylation of histones in the vicinity of the late origin ARS1412 by recruitment of the histone acetyltransferase Gcn5p causes ARS1412 alone to fire earlier. These data indicate that histone acetylation is a direct determinant of the timing of origin firing.