67 research outputs found
Complete chloroplast genome sequence of Holoparasite Cistanche Deserticola (Orobanchaceae) reveals gene loss and horizontal gene transfer from Its host Haloxylon Ammodendron (Chenopodiaceae)
The central function of chloroplasts is to carry out photosynthesis, and its gene content and structure are highly conserved across land plants. Parasitic plants, which have reduced photosynthetic ability, suffer gene losses from the chloroplast (cp) genome accompanied by the relaxation of selective constraints. Compared with the rapid rise in the number of cp genome sequences of photosynthetic organisms, there are limited data sets from parasitic plants. The authors report the complete sequence of the cp genome of Cistanche deserticola, a holoparasitic desert species belonging to the family Orobanchaceae
Ribosomal S6 Kinase 2 (RSK2) Maintains Genomic Stability by Activating the Atm/p53-Dependent DNA Damage Pathway
10.1371/journal.pone.0074334PLoS ONE89-POLN
Regulation of microRNA biogenesis and turnover by animals and their viruses
Item does not contain fulltextMicroRNAs (miRNAs) are a ubiquitous component of gene regulatory networks that modulate the precise amounts of proteins expressed in a cell. Despite their small size, miRNA genes contain various recognition elements that enable specificity in when, where and to what extent they are expressed. The importance of precise control of miRNA expression is underscored by functional studies in model organisms and by the association between miRNA mis-expression and disease. In the last decade, identification of the pathways by which miRNAs are produced, matured and turned-over has revealed many aspects of their biogenesis that are subject to regulation. Studies in viral systems have revealed a range of mechanisms by which viruses target these pathways through viral proteins or non-coding RNAs in order to regulate cellular gene expression. In parallel, a field of study has evolved around the activation and suppression of antiviral RNA interference (RNAi) by viruses. Virus encoded suppressors of RNAi can impact miRNA biogenesis in cases where miRNA and small interfering RNA pathways converge. Here we review the literature on the mechanisms by which miRNA biogenesis and turnover are regulated in animals and the diverse strategies that viruses use to subvert or inhibit these processes
Development of a multi-dimensional measure of resilience in adolescents: the Adolescent Resilience Questionnaire
Background: The concept of resilience has captured the imagination of researchers and policy makers over the past two decades. However, despite the ever growing body of resilience research, there is a paucity of relevant, comprehensive measurement tools. In this article, the development of a theoretically based, comprehensive multidimensional measure of resilience in adolescents is described.Methods: Extensive literature review and focus groups with young people living with chronic illness informed the conceptual development of scales and items. Two sequential rounds of factor and scale analyses were undertaken to revise the conceptually developed scales using data collected from young people living with a chronic illness and a general population sample.Results: The revised Adolescent Resilience Questionnaire comprises 93 items and 12 scales measuring resilience factors in the domains of self, family, peer, school and community. All scales have acceptable alpha coefficients. Revised scales closely reflect conceptually developed scales.Conclusions: It is proposed that, with further psychometric testing, this new measure of resilience will provide researchers and clinicians with a comprehensive and developmentally appropriate instrument to measure a young person’s capacity to achieve positive outcomes despite life stressors.<br /
Signatures of Selection in Fusion Transcripts Resulting From Chromosomal Translocations in Human Cancer
BACKGROUND: The recurrence and non-random distribution of translocation breakpoints in human tumors are usually attributed to local sequence features present in the vicinity of the breakpoints. However, it has also been suggested that functional constraints might contribute to delimit the position of translocation breakpoints within the genes involved, but a quantitative analysis of such contribution has been lacking. METHODOLOGY: We have analyzed two well-known signatures of functional selection, such as reading-frame compatibility and non-random combinations of protein domains, on an extensive dataset of fusion proteins resulting from chromosomal translocations in cancer. CONCLUSIONS: Our data provide strong experimental support for the concept that the position of translocation breakpoints in the genome of cancer cells is determined, to a large extent, by the need to combine certain protein domains and to keep an intact reading frame in fusion transcripts. Additionally, the information that we have assembled affords a global view of the oncogenic mechanisms and domain architectures that are used by fusion proteins. This can be used to assess the functional impact of novel chromosomal translocations and to predict the position of breakpoints in the genes involved
Roles of the creatine kinase system and myoglobin in maintaining energetic state in the working heart
<p>Abstract</p> <p>Background</p> <p>The heart is capable of maintaining contractile function despite a transient decrease in blood flow and increase in cardiac ATP demand during systole. This study analyzes a previously developed model of cardiac energetics and oxygen transport to understand the roles of the creatine kinase system and myoglobin in maintaining the ATP hydrolysis potential during beat-to-beat transient changes in blood flow and ATP hydrolysis rate.</p> <p>Results</p> <p>The theoretical investigation demonstrates that elimination of myoglobin only slightly increases the predicted range of oscillation of cardiac oxygenation level during beat-to-beat transients in blood flow and ATP utilization. In silico elimination of myoglobin has almost no impact on the cytoplasmic ATP hydrolysis potential (Δ<it>G</it><sub>ATPase</sub>). In contrast, disabling the creatine kinase system results in considerable oscillations of cytoplasmic ADP and ATP levels and seriously deteriorates the stability of Δ<it>G</it><sub>ATPase </sub>in the beating heart.</p> <p>Conclusion</p> <p>The CK system stabilizes Δ<it>G</it><sub>ATPase </sub>by both buffering ATP and ADP concentrations and enhancing the feedback signal of inorganic phosphate in regulating mitochondrial oxidative phosphorylation.</p
Mechanisms of Risk and Resilience in Military Families: Theoretical and Empirical Basis of a Family-Focused Resilience Enhancement Program
Recent studies have confirmed that repeated wartime deployment of a parent exacts a toll on military children and families and that the quality and functionality of familial relations is linked to force preservation and readiness. As a result, family-centered care has increasingly become a priority across the military health system. FOCUS (Families OverComing Under Stress), a family-centered, resilience-enhancing program developed by a team at UCLA and Harvard Schools of Medicine, is a primary initiative in this movement. In a large-scale implementation project initiated by the Bureau of Navy Medicine, FOCUS has been delivered to thousands of Navy, Marine, Navy Special Warfare, Army, and Air Force families since 2008. This article describes the theoretical and empirical foundation and rationale for FOCUS, which is rooted in a broad conception of family resilience. We review the literature on family resilience, noting that an important next step in building a clinically useful theory of family resilience is to move beyond developing broad “shopping lists” of risk indicators by proposing specific mechanisms of risk and resilience. Based on the literature, we propose five primary risk mechanisms for military families and common negative “chain reaction” pathways through which they undermine the resilience of families contending with wartime deployments and parental injury. In addition, we propose specific mechanisms that mobilize and enhance resilience in military families and that comprise central features of the FOCUS Program. We describe these resilience-enhancing mechanisms in detail, followed by a discussion of the ways in which evaluation data from the program’s first 2 years of operation supports the proposed model and the specified mechanisms of action
Cardiac resynchronization therapy guided by cardiovascular magnetic resonance
Cardiac resynchronization therapy (CRT) is an established treatment for patients with symptomatic heart failure, severely impaired left ventricular (LV) systolic dysfunction and a wide (> 120 ms) complex. As with any other treatment, the response to CRT is variable. The degree of pre-implant mechanical dyssynchrony, scar burden and scar localization to the vicinity of the LV pacing stimulus are known to influence response and outcome. In addition to its recognized role in the assessment of LV structure and function as well as myocardial scar, cardiovascular magnetic resonance (CMR) can be used to quantify global and regional LV dyssynchrony. This review focuses on the role of CMR in the assessment of patients undergoing CRT, with emphasis on risk stratification and LV lead deployment
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