Global Mapping of DNA Conformational Flexibility on Saccharomyces cerevisiae

In this study we provide the first comprehensive map of DNA conformational flexibility in Saccharomyces cerevisiae complete genome. Flexibility plays a key role in DNA supercoiling and DNA/protein binding, regulating DNA transcription, replication or repair. Specific interest in flexibility analysis concerns its relationship with human genome instability. Enrichment in flexible sequences has been detected in unstable regions of human genome defined fragile sites, where genes map and carry frequent deletions and rearrangements in cancer. Flexible sequences have been suggested to be the determinants of fragile gene proneness to breakage; however, their actual role and properties remain elusive. Our in silico analysis carried out genome-wide via the StabFlex algorithm, shows the conserved presence of highly flexible regions in budding yeast genome as well as in genomes of other Saccharomyces sensu stricto species. Flexibile peaks in S. cerevisiae identify 175 ORFs mapping on their 3’UTR, a region affecting mRNA translation, localization and stability. (TA)n repeats of different extension shape the central structure of peaks and co-localize with polyadenylation efficiency element (EE) signals. ORFs with flexible peaks share common features. Transcripts are characterized by decreased half-life: this is considered peculiar of genes involved in regulatory systems with high turnover; consistently, their function affects biological processes such as cell cycle regulation or stress response. Our findings support the functional importance of flexibility peaks, suggesting that the flexible sequence may be derived by an expansion of canonical TAYRTA polyadenylation efficiency element. The flexible (TA)n repeat amplification could be the outcome of an evolutionary neofunctionalization leading to a differential 3’-end processing and expression regulation in genes with peculiar function. Our study provides a new support to the functional role of flexibility in genomes and a strategy for its characterization inside human fragile sites

The mechanism of DNA unwinding by the eukaryotic replicative helicase

Accurate DNA replication is tightly regulated in eukaryotes to ensure genome stability during cell division and is performed by the multi-protein replisome. At the core an AAA+ hetero-hexameric complex, Mcm2-7, together with GINS and Cdc45 form the active replicative helicase Cdc45/Mcm2-7/GINS (CMG). It is not clear how this replicative ring helicase translocates on, and unwinds, DNA. We measure real-time dynamics of purified recombinant Drosophila melanogaster CMG unwinding DNA with single-molecule magnetic tweezers. Our data demonstrates that CMG exhibits a biased random walk, not the expected unidirectional motion. Through building a kinetic model we find CMG may enter up to three paused states rather than unwinding, and should these be prevented, in vivo fork rates would be recovered in vitro. We propose a mechanism in which CMG couples ATP hydrolysis to unwinding by acting as a lazy Brownian ratchet, thus providing quantitative understanding of the central process in eukaryotic DNA replication

Attachment insecurity, mentalization and their relation to symptoms in eating disorder patients

Objective: To investigate the relationships of attachment security and mentalization with core and co-morbid symptoms in eating disorder patients. Method: We compared 51 eating disorder patients at the start of intensive treatment and 20 healthy controls on attachment, mentalization, eating disorder symptoms, depression, anxiety, personality disorders, psycho-neuroticism, autonomy problems and self-injurious behavior, using the Adult Attachment Interview, the SCID-I and II and several questionnaires. Results: Compared with the controls, the eating disorder patients showed a higher prevalence of insecure attachment; eating disorder patients more often than controls received the AAI classification Unresolved for loss or abuse. They also had a lower level of mentalization and more autonomy problems. In the patient group eating disorder symptoms, depression, anxiety, psycho-neuroticism and autonomy problems were neither related to attachment security nor to mentalization; self-injurious behavior was associated with lesser attachment security and lower mentalization; borderline personality disorder was related to lower mentalization. In the control group no relations were found between attachment, mentalization and psychopathologic variables. Discussion: Eating disorder patients’ low level of mentalization suggests the usefulness of Mentalization Based Treatment techniques for eating disorder treatment, especially in case of self-injurious behavior and/or co-morbid borderline personality disorder

Attachment insecurity, mentalization and their relation to symptoms in eating disorder patients

Objective: To investigate the relationships of attachment security and mentalization with core and co-morbid symptoms in eating disorder patients. Method: We compared 51 eating disorder patients at the start of intensive treatment and 20 healthy controls on attachment, mentalization, eating disorder symptoms, depression, anxiety, personality disorders, psycho-neuroticism, autonomy problems and self-injurious behavior, using the Adult Attachment Interview, the SCID-I and II and several questionnaires. Results: Compared with the controls, the eating disorder patients showed a higher prevalence of insecure attachment; eating disorder patients more often than controls received the AAI classification Unresolved for loss or abuse. They also had a lower level of mentalization and more autonomy problems. In the patient group eating disorder symptoms, depression, anxiety, psycho-neuroticism and autonomy problems were neither related to attachment security nor to mentalization; self-injurious behavior was associated with lesser attachment security and lower mentalization; borderline personality disorder was related to lower mentalization. In the control group no relations were found between attachment, mentalization and psychopathologic variables. Discussion: Eating disorder patients’ low level of mentalization suggests the usefulness of Mentalization Based Treatment techniques for eating disorder treatment, especially in case of self-injurious behavior and/or co-morbid borderline personality disorder

Assessing the long-term health impact of Q-fever in the Netherlands: a prospective cohort study started in 2007 on the largest documented Q-fever outbreak to date

Contains fulltext : 109847.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Between 2007 and 2011, the Netherlands experienced the largest documented Q-fever outbreak to date with a total of 4108 notified acute Q-fever patients. Previous studies have indicated that Q-fever patients may suffer from long-lasting health effects, such as fatigue and reduced quality of life. Our study aims to determine the long-term health impact of Q-fever. It will also compare the health status of Q-fever patients with three reference groups: 1) healthy controls, 2) patients with Legionnaires' disease and 3) persons with a Q-fever infection but a-specific symptoms. METHODS/DESIGN: Two groups of Q-fever patients were included in a prospective cohort study. In the first group the onset of illness was in 2007-2008 and participation was at 12 and 48 months. In the second group the onset of illness was in 2010-2011 and participation was at 6 time intervals, from 3 to 24 months. The reference groups were included at only one time interval. The subjective health status, fatigue status and quality of life of patients will be assessed using two validated quality of life questionnaires. DISCUSSION: This study is the largest prospective cohort study to date that focuses on the effects of acute Q-fever. It will determine the long-term (up to 4 years) health impact of Q-fever on patients and compare this to three different reference groups so that we can present a comprehensive assessment of disease progression over time