397 research outputs found

    Multiboson threshold production by fermion-antifermion pair and hidden symmetry

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    We consider threshold production of arbitrary number of Higgs particles by fermion-antifermion pair. The nullification of amplitudes for the special case Higgs mass = 2 * fermion mass is explained in terms of hidden symmetry of the reduced effective dynamics.Comment: 8 pages, no figure

    Intonation of Greek in contact with Turkish: A diachronic study

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    Asia Minor Greek (AMG) speakers cohabited with Turkish speakers for eight hundred years until the 1923 Lausanne Convention, which forced a two-way mass population exchange between Turkey and Greece and severed their everyday contact. We compare the intonation of the continuation rise tune in the speech of first-generation AMG speakers born in Turkey with three subsequent generations born in Greece. We examine how long contact effects in intonation persist after contact has ceased, through comparison of the f0 patterns in four generations of AMG speakers with those of their Athenian Greek- and Turkish-speaking contemporaries. The speech of the first-generation of AMG speakers exhibits two patterns in the f0 curve shape and time alignment of the continuation rises, one Athenian-like and one Turkish-like. Over subsequent generations use of the latter diminishes, while the Athenian pattern becomes more frequent, indicating intergenerational change.Academy of Athens ; Economic and Social Research Counci

    Using serum CA125 to assess the activity of potential cytostatic agents in ovarian cancer

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    Objective: New strategies are required to rapidly identify novel cytostatic agents before embarking on large randomized trials. This study investigates whether a change in rate of rise (slope) of serum CA125 from before to after starting a novel agent could be used to identify cytostatic agents. Tamoxifen was used to validate this hypothesis. Methods: Asymptomatic patients with relapsed ovarian cancer who had responded to chemotherapy were enrolled and had CA125 measurements taken every 4 weeks, then more frequently when rising. Once levels reached 4 times the upper limit of normal or nadir, they started continuous tamoxifen 20 mg daily, as well as fortnightly CA125 measurements until symptomatic progression. Because of the potentially nonlinear relationship of CA125 over time, it was felt that to enable normal approximations to be utilized a natural logarithmic standard transformation [ln(CA125)] was the most suitable to improve linearity above the common logarithmic transformation to base 10. Results: From 235 recruited patients, 81 started tamoxifen and had at least 4 CA125 measurements taken before and 4 CA125 measurements taken after starting tamoxifen, respectively. The mean regression slopes from using at least 4 1n(CA125) measurements immediately before and after starting tamoxifen were 0I0149 and 0I0093 [ln(CA125)/d], respectively. This difference is statistically significant, P = 0I001. Therefore, in a future trial with a novel agent, at least as effective as tamoxifen, using this effect size, the number of evaluable patients needed, at significance level of 5% and power of 80%, is 56. Conclusions: Further validation of this methodology is required, but there is potential to use comparison of mean regression slopes of ln(CA125) as an interim analysis measure of efficacy for novel cytostatic agents in relapsed ovarian cancer.Peer reviewedFinal Accepted Versio

    CCCTC-binding factor recruitment to the early region of the human papillomavirus 18 genome regulates viral oncogene expression.

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    UNLABELLED: Host cell differentiation-dependent regulation of human papillomavirus (HPV) gene expression is required for productive infection. The host cell CCCTC-binding factor (CTCF) functions in genome-wide chromatin organization and gene regulation. We have identified a conserved CTCF binding site in the E2 open reading frame of high-risk HPV types. Using organotypic raft cultures of primary human keratinocytes containing high-risk HPV18 genomes, we show that CTCF recruitment to this conserved site regulates viral gene expression in differentiating epithelia. Mutation of the CTCF binding site increases the expression of the viral oncoproteins E6 and E7 and promotes host cell proliferation. Loss of CTCF binding results in a reduction of a specific alternatively spliced transcript expressed from the early gene region concomitant with an increase in the abundance of unspliced early transcripts. We conclude that high-risk HPV types have evolved to recruit CTCF to the early gene region to control the balance and complexity of splicing events that regulate viral oncoprotein expression. IMPORTANCE: The establishment and maintenance of HPV infection in undifferentiated basal cells of the squamous epithelia requires the activation of a subset of viral genes, termed early genes. The differentiation of infected cells initiates the expression of the late viral transcripts, allowing completion of the virus life cycle. This tightly controlled balance of differentiation-dependent viral gene expression allows the virus to stimulate cellular proliferation to support viral genome replication with minimal activation of the host immune response, promoting virus productivity. Alternative splicing of viral mRNAs further increases the complexity of viral gene expression. In this study, we show that the essential host cell protein CTCF, which functions in genome-wide chromatin organization and gene regulation, is recruited to the HPV genome and plays an essential role in the regulation of early viral gene expression and transcript processing. These data highlight a novel virus-host interaction important for HPV pathogenicity.CP was supported by a PhD studentship funded by the University of St Andrews, School of Medicine. IP is supported by a Cancer Research UK (CRUK) PhD Studentship awarded to JLP and SR. IG and NC are supported by a CRUK Programme Award (13080) to NC. JLP is supported by a Royal Society University Research Fellowship (UF110010).This is the final version of the article. It first appeared from American Society for Microbiology via http://dx.doi.org/10.1128/JVI.00097-1

    Assessment of the Effectiveness and Cost-Effectiveness of Tailored Web- and Text-Based Smoking Cessation Support in Primary Care (iQuit in Practice II): Protocol for a Randomized Controlled Trial.

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    BACKGROUND: The prevalence of smoking is declining; however, it continues to be a major public health burden. In England, primary care is the health setting that provides smoking cessation support to most smokers. However, this setting has one of the lowest success rates. The iQuit in practice intervention (iQuit) is a tailored web-based and text message intervention developed for use in primary care consultations as an adjunct to routine smoking cessation support with the aim of increasing success rates. iQuit has demonstrated feasibility, acceptability, and potential effectiveness. OBJECTIVE: This definitive trial aims to determine the effectiveness and cost-effectiveness of iQuit when used as an adjunct to the usual support provided to patients who wish to quit smoking, compared with usual care alone. METHODS: The iQuit in Practice II trial is a two-arm, parallel-group, randomized controlled trial (RCT) with a 1:1 individual allocation comparing usual care (ie, pharmacotherapy combined with multisession behavioral support)-the control-with usual care plus iQuit-the intervention. Participants were recruited through primary care clinics and talked to a smoking cessation advisor. Participants were randomized during the initial consultation, and those allocated to the intervention group received a tailored advice report and 90 days of text messaging in addition to the standard support provided to all patients. RESULTS: The primary outcome is self-reported prolonged abstinence biochemically verified using saliva cotinine at 6 months after the quit date. A sample size of 1700 participants, with 850 per arm, would yield 90% power to detect a 4.3% difference in validated quit rates between the groups at the two-sided 5% level of significance. The Cambridge East Research Ethics Committee approved the study in February 2016, and funding for the study was granted from May 2016. In total, 1671 participants were recruited between August 2016 and July 2019. Follow-up for all participants was completed in January 2020. Data analysis will begin in the summer of 2020. CONCLUSIONS: iQuit in Practice II is a definitive, pragmatic RCT assessing whether a digital intervention can augment the impact of routine smoking cessation support in primary care. Previous research has found good acceptability and feasibility for delivering iQuit among smoking cessation advisors working in primary care. If demonstrated to be cost-effective, iQuit could be delivered across primary care and other settings, such as community pharmacies. The potential benefit would likely be highest where less behavioral support is delivered. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN): 44559004; http://www.isrctn.com /ISRCTN44559004. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/17160

    BRCA1 and BRCA2 mutations in a population-based study of male breast cancer

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    Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear. Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk. Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives. Conclusion: These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found

    STAT3 activation by E6 is essential for the differentiation-dependent HPV18 life cycle.

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    Human papillomaviruses (HPV) activate a number of host factors to control their differentiation-dependent life cycles. The transcription factor signal transducer and activator of transcription (STAT)-3 is important for cell cycle progression and cell survival in response to cytokines and growth factors. STAT3 requires phosphorylation on Ser727, in addition to phosphorylation on Tyr705 to be transcriptionally active. In this study, we show that STAT3 is essential for the HPV life cycle in undifferentiated and differentiated keratinocytes. Primary human keratinocytes containing high-risk HPV18 genomes display enhanced STAT3 phosphorylation compared to normal keratinocytes. Expression of the E6 oncoprotein is sufficient to induce the dual phosphorylation of STAT3 at Ser727 and Tyr705 by a mechanism requiring Janus kinases and members of the MAPK family. E6-mediated activation of STAT3 induces the transcription of STAT3 responsive genes including cyclin D1 and Bcl-xL. Silencing of STAT3 protein expression by siRNA or inhibition of STAT3 activation by small molecule inhibitors, or by expression of dominant negative STAT3 phosphorylation site mutants, results in blockade of cell cycle progression. Loss of active STAT3 impairs HPV gene expression and prevents episome maintenance in undifferentiated keratinocytes and upon differentiation, lack of active STAT3 abolishes virus genome amplification and late gene expression. Organotypic raft cultures of HPV18 containing keratinocytes expressing a phosphorylation site STAT3 mutant display a profound reduction in suprabasal hyperplasia, which correlates with a loss of cyclin B1 expression and increased differentiation. Finally, increased STAT3 expression and phosphorylation is observed in HPV positive cervical disease biopsies compared to control samples, highlighting a role for STAT3 activation in cervical carcinogenesis. In summary, our data provides evidence of a critical role for STAT3 in the HPV18 life cycle

    An Adaptable, Portable Microarray Reader for Biodetection

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    We have developed an inexpensive portable microarray reader that can be applied to standard microscope slide-based arrays and other array formats printed on chemically modified surfaces. Measuring only 19 cm in length, the imaging device is portable and may be applicable to both triage and clinical settings. For multiplexing and adaptability purposes, it can be modified to work with multiple excitation/emission wavelengths. Our device is shown to be comparable to a commercial laser scanner when detecting both streptavidin-biotin and antibody interactions. This paper presents the development and characterization of a handheld microarray imager and directly compares it with a commercial scanner

    Disruption of CTCF-YY1-dependent looping of the human papillomavirus genome activates differentiation-induced viral oncogene transcription.

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    The complex life cycle of oncogenic human papillomavirus (HPV) initiates in undifferentiated basal epithelial keratinocytes where expression of the E6 and E7 oncogenes is restricted. Upon epithelial differentiation, E6/E7 transcription is increased through unknown mechanisms to drive cellular proliferation required to support virus replication. We report that the chromatin-organising CCCTC-binding factor (CTCF) promotes the formation of a chromatin loop in the HPV genome that epigenetically represses viral enhancer activity controlling E6/E7 expression. CTCF-dependent looping is dependent on the expression of the CTCF-associated Yin Yang 1 (YY1) transcription factor and polycomb repressor complex (PRC) recruitment, resulting in trimethylation of histone H3 at lysine 27. We show that viral oncogene up-regulation during cellular differentiation results from YY1 down-regulation, disruption of viral genome looping, and a loss of epigenetic repression of viral enhancer activity. Our data therefore reveal a key role for CTCF-YY1-dependent looping in the HPV life cycle and identify a regulatory mechanism that could be disrupted in HPV carcinogenesis
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