A single hydrophobic cleft in the Escherichia coli processivity clamp is sufficient to support cell viability and DNA damage-induced mutagenesis in vivo

<p>Abstract</p> <p>Background</p> <p>The ubiquitous family of DnaN sliding processivity clamp proteins plays essential roles in DNA replication, DNA repair, and cell cycle progression, in part by managing the actions of the different proteins involved in these processes. Interactions of the homodimeric <it>Escherichia coli </it>β clamp with its known partners involves multiple surfaces, including a hydrophobic cleft located near the C-terminus of each clamp protomer.</p> <p>Results</p> <p>A mutant <it>E. coli </it>β clamp protein lacking a functional hydrophobic cleft (β^C) complemented the temperature sensitive growth phenotype of a strain bearing the <it>dnaN159 </it>allele, which encodes a thermolabile mutant clamp protein (β159). Complementation was conferred by a β^C/β159 heterodimer, and was observed only in the absence of the <it>dinB </it>gene, which encodes DNA polymerase IV (Pol IV). Furthermore, the complemented strain was proficient for <it>umuDC </it>(Pol V) -dependent ultraviolet light (UV) -induced mutagenesis.</p> <p>Conclusions</p> <p>Our results suggest that a single cleft in the homodimeric <it>E. coli </it>β sliding clamp protein is sufficient to support both cell viability, as well as Pol III, Pol IV, and Pol V function <it>in vivo</it>. These findings provide further support for a model in which different Pols switch places with each other on DNA using a single cleft in the clamp.</p

Expressive and receptive use of speech and graphic symbols by typically developing children: What skills contribute to performance on structured sentence-level tasks?

Purpose: To explore expressive and receptive use of speech and graphic symbols and relationships with linguistic and cognitive skills in children with typical development. Method: Participants were 82 children with typical development (4 to 9 years). Measures of memory, visual analysis skills, and receptive language were used, along with five experimental tasks with speech or symbols as input (stimulus) or output (response), using single clause and compound clause stimuli. Cluster analysis grouped participants with similar performances patterns, who were then compared on linguistic and cognitive skill measures. Result: The lowest performing group sometimes accurately interpreted graphic symbol utterances that were visible during responding. The mid-performing group was stronger on expressive than receptive symbol utterances when the model did not remain visible. The highest group was comparable on expressive and receptive symbol tasks, but nonetheless stronger with spoken utterances. Relationships of linguistic and cognitive skills with task performance differed across the clusters. Conclusion: The findings help clarify the input-output modality asymmetry in graphic symbol communication. Spoken language proficiency does not directly transfer to sentence-level expressive and receptive graphic symbol use. Exploring potentially challenging sentence-level phenomena is important. Research is warranted to explore developmental progressions and potential clinical applications more systematically

An online study combining the constructs from the theory of planned behaviour and protection motivation theory in predicting intention to test for chlamydia in two testing contexts

Chlamydia is a common sexually-transmitted infection that has potentially serious consequences unless detected and treated early. The health service in the UK offers clinic-based testing for chlamydia but uptake is low. Identifying the predictors of testing behaviours may inform interventions to increase uptake. Self-tests for chlamydia may facilitate testing and treatment in people who avoid clinic-based testing. Self-testing and being tested by a health care professional (HCP) involve two contrasting contexts that may influence testing behaviour. However, little is known about how predictors of behaviour differ as a function of context. In this study, theoretical models of behaviour were used to assess factors that may predict intention to test in two different contexts: self-testing and being tested by a HCP. Individuals searching for, or reading about chlamydia testing online were recruited using Google Adwords. Participants completed an online questionnaire that addressed previous testing behaviour and measured constructs of the Theory of Planned Behaviour and Protection Motivation Theory, which propose a total of eight possible predictors of intention. The questionnaire was completed by 310 participants. Sufficient data for multiple regression were provided by 102 and 118 respondents for self-testing and testing by a HCP respectively. Intention to self-test was predicted by vulnerability and self-efficacy, with a trend-level effect for response efficacy. Intention to be tested by a HCP was predicted by vulnerability, attitude and subjective norm. Thus, intentions to carry out two testing behaviours with very similar goals can have different predictors depending on test context. We conclude that interventions to increase self-testing should be based on evidence specifically related to test context

Standardizing gross descriptions of skin lesions in common bottlenose dolphins (Tursiops truncatus) stranded in Southwest Florida, 2015–2019

As the first line of defense, the integumentary system is critical in comprehensively evaluating dolphin morbidity during stranding response. Most published studies on skin lesions in bottlenose dolphins (Tursiops truncatus) lack standardized gross descriptions and methodologies for evaluating lesions. The primary objective of this study was to evaluate the effectiveness of an assessment matrix designed to consistently describe skin lesions based on a set of standardized gross description characteristics. The matrix was implemented by reviewing necropsy reports, histopathology reports, and photographs collected from bottlenose dolphins stranded in Southwest Florida from 2015 through 2019. Of the 32 dolphins that met the inclusion criteria, 19 presented with skin lesions and five reviewers described each of the 46 lesions according to a novel, standardized assessment matrix. The most common descriptor selected, in each of the respective matrix categories, were, by anatomic location, head; distribution, multifocal to coalescing; quantity, moderate (10–30); size, &lt;2 cm; shape, punctate; margin, rounded; color modifier, hyperpigmentation; texture, smooth; and texture modifier, flat. These prevalent descriptors coincided with the frequent occurrence of histologically described hydropic degeneration (n=7, 15.2%) and were confirmed poxviral lesions in 6.52% (n=3). Identifying lesion patterns using standardized descriptors capitalizes on the unique pathogen tissue tropism and the implementation of certain disease mechanisms in the integumentary system. Therefore, it can facilitate differential disease diagnoses and guide ancillary diagnostics testing. The use of standardized descriptors will aid in etiologic identification and monitoring of skin lesions and associated diseases, advancing our understanding of dolphin morbidity and mortality

A powerful intervention: general practitioners' use of sickness certification in depression

&lt;b&gt;Background&lt;/b&gt; Depression is frequently cited as the reason for sickness absence, and it is estimated that sickness certificates are issued in one third of consultations for depression. Previous research has considered GP views of sickness certification but not specifically in relation to depression. This study aimed to explore GPs views of sickness certification in relation to depression.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; A purposive sample of GP practices across Scotland was selected to reflect variations in levels of incapacity claimants and antidepressant prescribing. Qualitative interviews were carried out between 2008 and 2009.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; A total of 30 GPs were interviewed. A number of common themes emerged including the perceived importance of GP advocacy on behalf of their patients, the tensions between stakeholders involved in the sickness certification system, the need to respond flexibly to patients who present with depression and the therapeutic nature of time away from work as well as the benefits of work. GPs reported that most patients with depression returned to work after a short period of absence and that it was often difficult to predict which patients would struggle to return to work.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; GPs reported that dealing with sickness certification and depression presents distinct challenges. Sickness certificates are often viewed as powerful interventions, the effectiveness of time away from work for those with depression should be subject to robust enquiry

Enhancing interprofessional collaboration and interprofessional education in women\u27s health

This article is from the \u27To The Point\u27 series from the Association of Professors of Gynecology and Obstetrics Undergraduate Medical Education Committee. The purpose of this review is to provide an understanding of the differing yet complementary nature of interprofessional collaboration and interprofessional education as well as their importance to the specialty of Obstetrics and Gynecology. We provide a historical perspective of how interprofessional collaboration and interprofessional education have become key aspects of clinical and educational programs, enhancing both patient care and learner development. Opportunities to incorporate interprofessional education within women\u27s health educational programs across organizations are suggested. This is a resource for medical educators, learners, and practicing clinicians from any field of medicine or any health-care profession

A Native Function for RAN Translation and CGG Repeats in Regulating Fragile X Protein Synthesis

Repeat-associated non-AUG-initiated translation of expanded CGG repeats (CGG RAN) from the FMR1 5′-leader produces toxic proteins that contribute to neurodegeneration in fragile X-associated tremor/ataxia syndrome. Here we describe how unexpanded CGG repeats and their translation play conserved roles in regulating fragile X protein (FMRP) synthesis. In neurons, CGG RAN acts as an inhibitory upstream open reading frame to suppress basal FMRP production. Activation of mGluR5 receptors enhances FMRP synthesis. This enhancement requires both the CGG repeat and CGG RAN initiation sites. Using non-cleaving antisense oligonucleotides (ASOs), we selectively blocked CGG RAN. This ASO blockade enhanced endogenous FMRP expression in human neurons. In human and rodent neurons, CGG RAN-blocking ASOs suppressed repeat toxicity and prolonged survival. These findings delineate a native function for CGG repeats and RAN translation in regulating basal and activity-dependent FMRP synthesis, and they demonstrate the therapeutic potential of modulating CGG RAN translation in fragile X-associated disorders

2019 American Heart Association focused update on pediatric advanced life support: An update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care

This 2019 focused update to the American Heart Association pediatric advanced life support guidelines follows the 2018 and 2019 systematic reviews performed by the Pediatric Life Support Task Force of the International Liaison Committee on Resuscitation. It aligns with the continuous evidence review process of the International Liaison Committee on Resuscitation, with updates published when the International Liaison Committee on Resuscitation completes a literature review based on new published evidence. This update provides the evidence review and treatment recommendations for advanced airway management in pediatric cardiac arrest, extracorporeal cardiopulmonary resuscitation in pediatric cardiac arrest, and pediatric targeted temperature management during post–cardiac arrest care. The writing group analyzed the systematic reviews and the original research published for each of these topics. For airway management, the writing group concluded that it is reasonable to continue bag-mask ventilation (versus attempting an advanced airway such as endotracheal intubation) in patients with out-of-hospital cardiac arrest. When extracorporeal membrane oxygenation protocols and teams are readily available, extracorporeal cardiopulmonary resuscitation should be considered for patients with cardiac diagnoses and in-hospital cardiac arrest. Finally, it is reasonable to use targeted temperature management of 32°C to 34°C followed by 36°C to 37.5°C, or to use targeted temperature management of 36°C to 37.5°C, for pediatric patients who remain comatose after resuscitation from out-of-hospital cardiac arrest or in-hospital cardiac arrest

Expectations of and for Clerkship Directors 2.0: A Collaborative Statement from the Alliance for Clinical Education

This article presents an update of the collaborative statement on clerkship directors (CDs), first published in 2003, from the national undergraduate medical education organizations that comprise the Alliance for Clinical Education (ACE). The clerkship director remains an essential leader in the education of medical students on core clinical rotations, and the role of the CD has and continues to evolve. The selection of a CD should be an explicit contract between the CD, their department, and the medical school, with each party fulfilling their obligations to ensure the success of the students, the clerkship and of the CD. Educational innovations and accreditation requirements have evolved in the last two decades and therefore this article updates the 2003 standards for what is expected of a CD and provides guidelines for the resources and support to be provided. In their roles as CDs, medical student educators engage in several critical activities: administration, education/teaching, coaching, advising, and mentoring, faculty development, compliance with accreditation standards, and scholarly activity. This article describes (a) the work products that are the primary responsibility of the CD; (b) the qualifications for the CD; (c) the support structure, resources, and personnel that are necessary for the CD to accomplish their responsibilities; (d) incentives and career development for the CD; and (e) the dedicated time that should be provided for the clerkship and the CD to succeed. Given all that should rightfully be expected of a CD, a minimum of 50% of a full-time equivalent is recognized as appropriate. The complexity and needs of the clerkship now require that at least one full-time clerkship administrator (CA) be a part of the CD’s team. To better reflect the current circumstances, ACE has updated its recommendations for institutions and departments to have clear standards for what is expected of the director of a clinical clerkship and have correspondingly clear guidelines as to what should be expected for CDs in the support they are provided. This work has been endorsed by each of the eight ACE member organizations

Lessons learned from additional research analyses of unsolved clinical exome cases

BACKGROUND: Given the rarity of most single-gene Mendelian disorders, concerted efforts of data exchange between clinical and scientific communities are critical to optimize molecular diagnosis and novel disease gene discovery. METHODS: We designed and implemented protocols for the study of cases for which a plausible molecular diagnosis was not achieved in a clinical genomics diagnostic laboratory (i.e. unsolved clinical exomes). Such cases were recruited to a research laboratory for further analyses, in order to potentially: (1) accelerate novel disease gene discovery; (2) increase the molecular diagnostic yield of whole exome sequencing (WES); and (3) gain insight into the genetic mechanisms of disease. Pilot project data included 74 families, consisting mostly of parent-offspring trios. Analyses performed on a research basis employed both WES from additional family members and complementary bioinformatics approaches and protocols. RESULTS: Analysis of all possible modes of Mendelian inheritance, focusing on both single nucleotide variants (SNV) and copy number variant (CNV) alleles, yielded a likely contributory variant in 36% (27/74) of cases. If one includes candidate genes with variants identified within a single family, a potential contributory variant was identified in a total of ~51% (38/74) of cases enrolled in this pilot study. The molecular diagnosis was achieved in 30/63 trios (47.6%). Besides this, the analysis workflow yielded evidence for pathogenic variants in disease-associated genes in 4/6 singleton cases (66.6%), 1/1 multiplex family involving three affected siblings, and 3/4 (75%) quartet families. Both the analytical pipeline and the collaborative efforts between the diagnostic and research laboratories provided insights that allowed recent disease gene discoveries (PURA, TANGO2, EMC1, GNB5, ATAD3A, and MIPEP) and increased the number of novel genes, defined in this study as genes identified in more than one family (DHX30 and EBF3). CONCLUSION: An efficient genomics pipeline in which clinical sequencing in a diagnostic laboratory is followed by the detailed reanalysis of unsolved cases in a research environment, supplemented with WES data from additional family members, and subject to adjuvant bioinformatics analyses including relaxed variant filtering parameters in informatics pipelines, can enhance the molecular diagnostic yield and provide mechanistic insights into Mendelian disorders. Implementing these approaches requires collaborative clinical molecular diagnostic and research efforts