198 research outputs found

    Duplex strand joining reactions catalyzed by vaccinia virus DNA polymerase

    Get PDF
    Vaccinia virus DNA polymerase catalyzes duplex-by-duplex DNA joining reactions in vitro and many features of these recombination reactions are reprised in vivo. This can explain the intimate linkage between virus replication and genetic recombination. However, it is unclear why these apparently ordinary polymerases exhibit this unusual catalytic capacity. In this study, we have used different substrates to perform a detailed investigation of the mechanism of duplex-by-duplex recombination catalyzed by vaccinia DNA polymerase. When homologous, blunt-ended linear duplex substrates are incubated with vaccinia polymerase, in the presence of Mg(2+) and dNTPs, the appearance of joint molecules is preceded by the exposure of complementary single-stranded sequences by the proofreading exonuclease. These intermediates anneal to form a population of joint molecules containing hybrid regions flanked by nicks, 1–5 nt gaps, and/or short overhangs. The products are relatively resistant to exonuclease (and polymerase) activity and thus accumulate in joining reactions. Surface plasmon resonance (SPR) measurements showed the enzyme has a relative binding affinity favoring blunt-ended duplexes over molecules bearing 3′-recessed gaps. Recombinant duplexes are the least favored ligands. These data suggest that a particular combination of otherwise ordinary enzymatic and DNA-binding properties, enable poxvirus DNA polymerases to promote duplex joining reactions

    Results of a Social Media Campaign to Prevent Indoor Tanning by Teens: A Randomized Controlled Trial

    Get PDF
    Indoor tanning (IT) increases risk of developing skin cancer. A social media campaign to reduce mother\u27s permissiveness toward their teenage daughters IT was evaluated. Mothers (N = 869) of daughters aged 14–17 in 34 states without bans on IT by minors were enrolled in a randomized trial with assessments at baseline and 12-months follow-up in 2017–19. A year-long adolescent health campaign was delivered to all mothers. The intervention group received posts on preventing IT and the control group, posts about preventing prescription drug misuse. Daughters (n = 469; 54.0%) completed the assessments at baseline and 12 months. At 12-month follow-up, intervention-group mothers were less permissive of IT by daughters (unadjusted means = 1.70 [95% CI: 1.59, 1.80] v. 1.85 [1.73, 1.97] [5-point Likert scale], b = -0.152), reported more communication about avoiding IT with daughters (4.09 [3.84, 4.35] v. 3.42 [3.16, 3.68] [sum of 7 yes/no items], b = 0.213), and had lower intentions to indoor tan (1.41 [1.28, 1.55] v. 1.60 [1.43, 1.76] [7-point likelihood scale], b = -0.221) than control-group mothers. Daughters confirmed intervention-group mothers communicated about IT (3.81 [3.49, 4.14] v. 3.20 [2.87, 3.53] [sum of 7 yes/no items], b = 0.237) and shared IT posts (unadjusted percentages = 52.4% v. 36.4%, b = 0.438) more than control-group mothers. No differences were found in IT behavior, self-efficacy to refuse permission, and negative attitudes toward IT. A social media campaign may be an effective strategy to convince mothers to withhold permission for IT, which may help increase the effectiveness of state laws designed to reduce IT by minors by requiring parental permission

    VennVax, a DNA-prime, peptide-boost multi-T-cell epitope poxvirus vaccine, induces protective immunity against vaccinia infection by T cell response alone

    Get PDF
    The potential for smallpox to be disseminated in a bioterror attack has prompted development of new, safer smallpox vaccination strategies. We designed and evaluated immunogenicity and efficacy of a T-cell epitope vaccine based on conserved and antigenic vaccinia/variola sequences, identified using bioinformatics and immunological methods. Vaccination in HLA transgenic mice using a DNA-prime/peptide-boost strategy elicited significant T cell responses to multiple epitopes. No antibody response pre-challenge was observed, neither against whole vaccinia antigens nor vaccine epitope peptides. Remarkably, 100% of vaccinated mice survived lethal vaccinia challenge, demonstrating that protective immunity to vaccinia does not require B cell priming

    Measures of sun exposure and sun protection practices for behavioural and epidemiological research

    Get PDF
    Objective: To develop, in a collaborative project, core measures of sun exposure and sun protection habits, since the lack of standard outcome measures hampers comparison of population surveys and interventions used in skin cancer prevention research. Design: A work group of investigators evaluated available questionnaire measures of sun exposure and protection. Their deliberations led to a proposed set of core questionnaire items for adults, adolescents aged 11 to 17 years, and children 10 years or younger. These core items were used in cognitive testing by the investigators. Cross-site summaries of methods, response samples, and descriptive data were prepared. Setting: Nine locations across the United States. Participants: The study population comprised 81 individuals. Results: No unusual response patterns were detected in any of the respondent groups or for any specific question. Some revisions to the survey items resulted from the need for clarification or emphasis of frames of reference such as adding or underlining key phrases in a question. Conclusions: The combination of expert review followed by cognitive interviewing yielded standardized core survey items with good clarity and applicability for measuring sun exposure and sun protection behaviors across a broad range of populations. They are appropriate for studies tracking morbidity and/or mortality and evaluating prevention program effects

    Engaging Moms on Teen Indoor Tanning Through Social Media: Protocol of a Randomized Controlled Trial

    Get PDF
    BACKGROUND: Indoor tanning elevates the risk for melanoma, which is now the most common cancer in US women aged 25-29. Public policies restricting access to indoor tanning by minors to reduce melanoma morbidity and mortality in teens are emerging. In the United States, the most common policy restricting indoor tanning in minors involves parents providing either written or in person consent for the minor to purchase a tanning visit. The effectiveness of this policy relies on parents being properly educated about the harms of indoor tanning to their children. OBJECTIVE: This randomized controlled trial will test the efficacy of a Facebook-delivered health communication intervention targeting mothers of teenage girls. The intervention will use health communication and behavioral modification strategies to reduce mothers\u27 permissiveness regarding their teenage daughters\u27 use of indoor tanning relative to an attention-control condition with the ultimate goal of reducing indoor tanning in both daughters and mothers. METHODS: The study is a 12-month randomized controlled trial comparing 2 conditions: an attention control Facebook private group where content will be relevant to teen health with 25% focused on prescription drug abuse, a topic unrelated to tanning; and the intervention condition will enter participants into a Facebook private group where 25% of the teen health content will be focused on indoor tanning. A cohort of 2000 mother-teen daughter dyads will be recruited to participate in this study. Only mothers will participate in the Facebook groups. Both mothers and daughters will complete measures at baseline, end of intervention (1-year) and 6 months post-intervention. Primary outcomes include mothers\u27 permissiveness regarding their teenage daughters\u27 use of indoor tanning, teenage daughters\u27 perception of their mothers\u27 permissiveness, and indoor tanning by both mothers and daughters. RESULTS: The first dyad was enrolled on March 31, 2016, and we anticipate completing this study by October 2019. CONCLUSIONS: This trial will deliver social media content grounded in theory and will test it in a randomized design with state-of-the-art measures. This will contribute much needed insights on how to employ social media for health behavior change and disease prevention both for indoor tanning and other health risk behaviors and inform future social media efforts by public health and health care organizations. CLINICALTRIAL: Clinicaltrials.gov NCT02835807; https://clinicaltrials.gov/ct2/show/NCT02835807 (Archived by WebCite at http://www.webcitation.org/6mDMICcCE)

    Epidemiology, co-infections, and outcomes of viral pneumonia in adults an observational cohort study

    Get PDF
    Advanced technologies using polymerase-chain reaction have allowed for increased recognition of viral respiratory infections including pneumonia. Co-infections have been described for several respiratory viruses, especially with influenza. Outcomes of viral pneumonia, including cases with co-infections, have not been well described. This was observational cohort study conducted to describe hospitalized patients with viral pneumonia including co-infections, clinical outcomes, and predictors of mortality. Patients admitted from March 2013 to November 2014 with a positive respiratory virus panel (RVP) and radiographic findings of pneumonia within 48 h of the index RVP were included. Co-respiratory infection (CRI) was defined as any organism identification from a respiratory specimen within 3 days of the index RVP. Predictors of in-hospital mortality on univariate analysis were evaluated in a multivariate model. Of 284 patients with viral pneumonia, a majority (51.8%) were immunocompromised. A total of 84 patients (29.6%) were found to have a CRI with 48 (57.6%) having a bacterial CRI. Viral CRI with HSV, CMV, or both occurred in 28 patients (33.3%). Fungal (16.7%) and other CRIs (7.1%) were less common. Many patients required mechanical ventilation (54%) and vasopressor support (36%). Overall in-hospital mortality was high (23.2%) and readmissions were common with several patients re-hospitalized within 30 (21.1%) and 90 days (36.7%) of discharge. Predictors of in-hospital mortality on multivariate regression included severity of illness factors, stem-cell transplant, and identification of multiple respiratory viruses. In conclusion, hospital mortality is high among adult patients with viral pneumonia and patients with multiple respiratory viruses identified may be at a higher risk

    TP53 mutations in ovarian carcinomas from sporadic cases and carriers of two distinct BRCA1 founder mutations; relation to age at diagnosis and survival

    Get PDF
    BACKGROUND: Ovarian carcinomas from 30 BRCA1 germ-line carriers of two distinct high penetrant founder mutations, 20 carrying the 1675delA and 10 the 1135insA, and 100 sporadic cases were characterized for somatic mutations in the TP53 gene. We analyzed differences in relation to BRCA1 germline status, TP53 status, survival and age at diagnosis, as previous studies have not been conclusive. METHODS: DNA was extracted from paraffin embedded formalin fixed tissues for the familial cases, and from fresh frozen specimen from the sporadic cases. All cases were treated at our hospital according to protocol. Mutation analyses of exon 2 – 11 were performed using TTGE, followed by sequencing. RESULTS: Survival rates for BRCA1-familial cases with TP53 mutations were not significantly lower than for familial cases without TP53 mutations (p = 0.25, RR = 1.64, 95% CI [0.71–3.78]). Median age at diagnosis for sporadic (59 years) and familial (49 years) cases differed significantly (p < 0.001) with or without TP53 mutations. Age at diagnosis between the two types of familial carriers were not significantly different, with median age of 47 for 1675delA and 52.5 for 1135insA carriers (p = 0.245). For cases ≥50 years at diagnosis, a trend toward longer survival for sporadic over familial cases was observed (p = 0.08). The opposite trend was observed for cases <50 years at diagnosis. CONCLUSION: There do not seem to be a protective advantage for familial BRCA1 carriers without TP53 mutations over familial cases with TP53 mutations. However, there seem to be a trend towards initial advantage in survival for familial cases compared to sporadic cases diagnosed before the age of 50 both with and without TP53 mutations. However, this trend diminishes over time and for cases diagnosed ≥50 years the sporadic cases show a trend towards an advantage in survival over familial cases. Although this data set is small, if confirmed, this may be a link in the evidence that the differences in ovarian cancer survival reported, are not due to the type of BRCA1 mutation, but may be secondary to genetic factors shared. This may have clinical implications for follow-up such as prophylactic surgery within carriers of the two most frequent Norwegian BRCA1 founder mutations

    Interdisciplinary Perspectives on Sun Safety and Skin Cancer Risk: achieving consensus

    Get PDF
    Overexposure to the sun is associated with an increased risk of melanoma and nonmelanoma skin cancer, but indications of improvements in sun protection behavior are poor. Attempts to identify emerging themes in skin cancer control have largely been driven by groups of experts from a single field. In December 2016, 19 experts from various disciplines convened for Interdisciplinary Perspectives on Skin Cancer, a 2-day meeting hosted by the National Academy of Sciences. The group discussed knowledge gaps, perspectives on sun exposure, implications for skin cancer risk and other health outcomes, and new directions. Five themes emerged from the discussion: (1) The definition of risk must be expanded, and categories for skin physiology must be refined to incorporate population diversities. (2) Risky sun exposure often co-occurs with other health-related behaviors. (3) Messages must be nuanced to target at-risk populations. (4) Persons at risk for tanning disorder must be recognized and treated. (5) Sun safety interventions must be scalable. Efficient use of technologies will be required to sharpen messages to specific populations and to integrate them within multilevel interventions. Further interdisciplinary research should address these emerging themes to build effective and sustainable approaches to large-scale behavior change

    Reducing ultraviolet radiation exposure among outdoor workers: State of the evidence and recommendations

    Get PDF
    <p>Abstract</p> <p>Objective</p> <p>Outdoor workers have high levels of exposure to ultraviolet radiation and the associated increased risk of skin cancer. This paper describes a review of: 1) descriptive data about outdoor workers' sun exposure and protection and related knowledge, attitudes, and policies and 2) evidence about the effectiveness of skin cancer prevention interventions in outdoor workplaces.</p> <p>Data sources</p> <p>Systematic evidence-based review.</p> <p>Data synthesis</p> <p>We found variable preventive practices, with men more likely to wear hats and protective clothing and women more likely to use sunscreen. Few data document education and prevention policies.</p> <p>Conclusion</p> <p>Reports of interventions to promote sun-safe practices and environments provide encouraging results, but yield insufficient evidence to recommend current strategies as effective. Additional efforts should focus on increasing sun protection policies and education programs in workplaces and evaluating whether they improve the health behavior of outdoor workers.</p

    Ancient DNA Resolves Identity and Phylogeny of New Zealand's Extinct and Living Quail (Coturnix sp.)

    Get PDF
    BACKGROUND: The New Zealand quail, Coturnix novaezealandiae, was widespread throughout New Zealand until its rapid extinction in the 1870's. To date, confusion continues to exist concerning the identity of C. novaezealandiae and its phylogenetic relationship to Coturnix species in neighbouring Australia, two of which, C. ypsilophora and C. pectoralis, were introduced into New Zealand as game birds. The Australian brown quail, C. ypsilophora, was the only species thought to establish with current populations distributed mainly in the northern part of the North Island of New Zealand. Owing to the similarities between C. ypsilophora, C. pectoralis, and C. novaezealandiae, uncertainty has arisen over whether the New Zealand quail is indeed extinct, with suggestions that remnant populations of C. novaezealandiae may have survived on offshore islands. METHODOLOGY/PRINCIPAL FINDINGS: Using fresh and historical samples of Coturnix sp. from New Zealand and Australia, DNA analysis of selected mitochondrial regions was carried out to determine phylogenetic relationships and species status. Results show that Coturnix sp. specimens from the New Zealand mainland and offshore island Tiritiri Matangi are not the New Zealand quail but are genetically identical to C. ypsilophora from Australia and can be classified as the same species. Furthermore, cytochrome b and COI barcoding analysis of the New Zealand quail and Australia's C. pectoralis, often confused in museum collections, show that they are indeed separate species that diverged approximately 5 million years ago (mya). Gross morphological analysis of these birds suggests a parallel loss of sustained flight with very little change in other phenotypic characters such as plumage or skeletal structure. CONCLUSION/SIGNIFICANCE: Ancient DNA has proved invaluable for the detailed analysis and identification of extinct and morphologically cryptic taxa such as that of quail and can provide insights into the timing of evolutionary changes that influence morphology
    • …
    corecore