205 research outputs found

    Issues of methods and interpretation in the National Cancer Institute formaldehyde cohort study

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    In 2004, the International Agency for Research on Cancer (IARC) reclassified formaldehyde (FA) from a probable (Group 2A) to a known human carcinogen (Group 1) citing results for nasopharyngeal cancer (NPC) mortality from the follow-up through 1994 of the National Cancer Institute formaldehyde cohort study. To the contrary, in 2012, the Committee for Risk Assessment of the European Chemicals Agency disagreed with the proposal to classify FA as a known human carcinogen (Carc. 1A), proposing a lower but still protective category, namely as a substance which is presumed to have carcinogenic potential for humans (Carc. 1B). Thus, U.S. and European regulatory agencies currently disagree about the potential human carcinogenicity of FA. In 2013, the National Cancer Institute reported results from their follow-up through 2004 of the formaldehyde cohort and concluded that the results continue to suggest a link between FA exposure and NPC. We discuss in this commentary why we believe that this interpretation is neither consistent with the available data from the most recent update of the National Cancer Institute cohort study nor with other research findings from that cohort, other large cohort studies and the series of publications by some of the current authors, including an independent study of one of the National Cancer Institute's study plants. Another serious concern relates to the incorrectness of the data from the follow-up through 1994 of the National Cancer Institute study stemming from incomplete mortality ascertainment. While these data were corrected by the National Cancer Institute in subsequent supplemental publications, incorrect data from the original publications have been cited extensively in recent causal evaluations of FA, including IARC. We conclude that the NCI publications that contain incorrect data from the incomplete 1994 mortality follow-up should be retracted entirely or corrected via published errata in the corresponding journals, and efforts should be made to re-analyze data from the 2004 follow-up of the NCI cohort study. © 2014 Marsh et al.; licensee BioMed Central Ltd

    Differential expression of the brassinosteroid receptor-encoding BRI1 gene in Arabidopsis

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    Abstract Brassinosteroid (BR)-regulated growth and development in Arabidopsis depends on BRASSINOSTEROID INSENSITIVE 1 (BRI1), the BR receptor that is responsible for initiating the events of BR signalling. We analysed the temporal and spatial regulation of BRI1 expression using stable transgenic lines that carried BRI1 promoter:reporter fusions. In both seedlings and mature plants the tissues undergoing elongation or differentiation showed elevated BRI1 gene activity, and it could be demonstrated that in the hypocotyl this was accompanied by accumulation of the BRI1 transcript and its receptor protein product. In seedlings the BRI1 promoter was also found to be under diurnal regulation, determined primarily by light repression and a superimposed circadian control. To determine the functional importance of transcriptional regulation we complemented the severely BR insensitive bri1-101 mutant with a BRI1-luciferase fusion construct that was driven by promoters with contrasting specificities. Whereas the BRI1 promoter-driven transgene fully restored the wild phenotype, expression from the photosynthesisassociated CAB3 and the vasculature-specific SUC2 and ATHB8 promoters resulted in plants with varying morphogenic defects. Our results reveal complex differential regulation of BRI1 expression, and suggest that by influencing the distribution and abundance of the receptor this regulation can enhance or attenuate BR signalling

    Viroids: survivors from the RNA world?

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    [EN] Because RNA can be a carrier of genetic information and a biocatalyst, there is a consensus that it emerged before DNA and proteins, which eventually assumed these roles and relegated RNA to intermediate functions. If such a scenarioÂżthe so-calledRNAworldÂżexisted,wemight hope to find its relics in our presentworld. The properties of viroids that make them candidates for being survivors of the RNA world include those expected for primitive RNA replicons: (a) small size imposed by error-prone replication, (b) high G + C content to increase replication fidelity, (c) circular structure for assuring complete replication without genomic tags, (d ) structural periodicity for modular assembly into enlarged genomes, (e) lack of protein-coding ability consistent with a ribosome-free habitat, and ( f ) replication mediated in some by ribozymes, the fingerprint of the RNA world. With the advent of DNA and proteins, those protoviroids lost some abilities and became the plant parasites we now know.R.F. has received funding by grant BFU2011-28443 from Ministerio de Economia y Competititvidad (MINECO, Spain), R.S. by grants BFU2011-25271 (MINECO) and ERC-2011-StG-281191-VIRMUT (European Research Council), and S.F.E. by grant BFU2012-30805 (MINECO). P.S. has been supported by postdoctoral contracts from Generalitat Valenciana (APOSTD/2010, program VALi+d) and MINECO (program Juan de la Cierva).Flores Pedauye, R.; Gago Zachert, SP.; Serra Alfonso, P.; Sanjuan Verdeguer, R.; Elena Fito, SF. (2014). Viroids: survivors from the RNA world?. Annual Review of Microbiology. 68:395-414. https://doi.org/10.1146/annurev-micro-091313-103416S3954146

    Effects of ambient air pollution on functional status in patients with chronic congestive heart failure: a repeated-measures study

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    <p>Abstract</p> <p>Background</p> <p>Studies using administrative data report a positive association between ambient air pollution and the risk of hospitalization for congestive heart failure (HF). Circulating levels of B-type natriuretic peptide (BNP) are directly associated with cardiac hemodynamics and symptom severity in patients with HF and, therefore, serves as a marker of functional status. We tested the hypothesis that BNP levels would be positively associated with short-term changes in ambient pollution levels among 28 patients with chronic stable HF and impaired systolic function.</p> <p>Methods</p> <p>BNP was measured in whole blood at 0, 6, and 12 weeks. We used linear mixed models to evaluate the association between fine particulate matter (PM<sub>2.5</sub>), carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone, and black carbon and log(BNP). Lags of 0 to 3 days were considered in separate models. We calculated the intraclass correlation coefficient and within-subject coefficient of variation as measures of reproducibility.</p> <p>Results</p> <p>We found no association between any pollutant and measures of BNP at any lag. For example, a 10 ÎŒg/m<sup>3 </sup>increase in PM<sub>2.5 </sub>was associated with a 0.8% (95% CI: -16.4, 21.5; p = 0.94) increase in BNP on the same day. The within-subject coefficient of variation was 45% on the natural scale and 9% on the log scale.</p> <p>Conclusion</p> <p>These results suggest that serial BNP measurements are unlikely to be useful in a longitudinal study of air pollution-related acute health effects. The magnitude of expected ambient air pollution health effects appears small in relation to the considerable within-person variability in BNP levels in this population.</p

    Stunned Silence: Gene Expression Programs in Human Cells Infected with Monkeypox or Vaccinia Virus

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    Poxviruses use an arsenal of molecular weapons to evade detection and disarm host immune responses. We used DNA microarrays to investigate the gene expression responses to infection by monkeypox virus (MPV), an emerging human pathogen, and Vaccinia virus (VAC), a widely used model and vaccine organism, in primary human macrophages, primary human fibroblasts and HeLa cells. Even as the overwhelmingly infected cells approached their demise, with extensive cytopathic changes, their gene expression programs appeared almost oblivious to poxvirus infection. Although killed (gamma-irradiated) MPV potently induced a transcriptional program characteristic of the interferon response, no such response was observed during infection with either live MPV or VAC. Moreover, while the gene expression response of infected cells to stimulation with ionomycin plus phorbol 12-myristate 13-acetate (PMA), or poly (I-C) was largely unimpaired by infection with MPV, a cluster of pro-inflammatory genes were a notable exception. Poly(I-C) induction of genes involved in alerting the innate immune system to the infectious threat, including TNF-alpha, IL-1 alpha and beta, CCL5 and IL-6, were suppressed by infection with live MPV. Thus, MPV selectively inhibits expression of genes with critical roles in cell-signaling pathways that activate innate immune responses, as part of its strategy for stealthy infection

    Agreement of Self-Reported and Genital Measures of Sexual Arousal in Men and Women: A Meta-Analysis

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    The assessment of sexual arousal in men and women informs theoretical studies of human sexuality and provides a method to assess and evaluate the treatment of sexual dysfunctions and paraphilias. Understanding measures of arousal is, therefore, paramount to further theoretical and practical advances in the study of human sexuality. In this meta-analysis, we review research to quantify the extent of agreement between self-reported and genital measures of sexual arousal, to determine if there is a gender difference in this agreement, and to identify theoretical and methodological moderators of subjective-genital agreement. We identified 132 peer- or academically-reviewed laboratory studies published between 1969 and 2007 reporting a correlation between self-reported and genital measures of sexual arousal, with total sample sizes of 2,505 women and 1,918 men. There was a statistically significant gender difference in the agreement between self-reported and genital measures, with men (r = .66) showing a greater degree of agreement than women (r = .26). Two methodological moderators of the gender difference in subjective-genital agreement were identified: stimulus variability and timing of the assessment of self-reported sexual arousal. The results have implications for assessment of sexual arousal, the nature of gender differences in sexual arousal, and models of sexual response
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