84 research outputs found

    A Comparative Study on the WCRF International/University of Bristol Methodology for Systematic Reviews of Mechanisms Underpinning Exposure-Cancer Associations

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    The World Cancer Research Fund (WCRF) International and the University of Bristol have developed a novel framework for providing an overview of mechanistic pathways and conducting a systematic literature review of the biologically plausible mechanisms underlying exposure-cancer associations. Two teams independently applied the two-stage framework on mechanisms underpinning the association between body fatness and breast cancer to test the framework feasibility and reproducibility as part of a WCRF-commissioned validation study. In stage I, a "hypothesis-free" approach was used to provide an overview of potential intermediate mechanisms between body fatness and breast cancer. Dissimilar rankings of potential mechanisms were observed between the two teams due to different applications of the framework. In stage II, a systematic review was conducted on the insulin-like growth factor 1 receptor (IGF1R) chosen as an intermediate mechanism. Although the studies included differed, both teams found inconclusive evidence for the body fatness-IGF1R association and modest evidence linking IGF1R to breast cancer, and therefore concluded that there is currently weak evidence for IGF1R as mechanism linking body fatness to breast cancer. The framework is a good starting point for conducting systematic reviews by integrating evidence from mechanistic studies on exposure-cancer associations. On the basis of our experience, we provide recommendations for future users. (C) 2017 AACR

    On the pulmonary toxicity of oxygen : III. The induction of oxygen dependency by oxygen use

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    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental and Molecular Pathology 89 (2010): 36-45, doi:10.1016/j.yexmp.2010.05.004.Oxygen is central to the development of neonatal lung injury. The increase in oxygen exposure of the neonatal lung during the onset of extrauterine air breathing is an order of magnitude, from a range of 10-12 to 110-120 Torr. The contributions of oxygen and the volume and pressure relationships of ventilatory support to lung injury are not easily distinguished in the clinical setting. Sequential changes in inspired air or 100% oxygen were studied in 536 newborn rabbits without ventilatory support. Bilateral cervical vagotomies (BCV) were performed at 24 hours post natal to induce ventilatory distress which eventuates in hyaline membrane disease. The sequences applied yielded evidence for an induced state of oxygen dependency from oxygen use which was reflected in differences in survival and the extent of pulmonary injury. The median survival for animals kept in air throughout was 3 hours. Oxygen before vagotomy or during the first 3 hours afterwards extended the survival significantly but produced more extensive, more severe, and more rapid lung lesions. Returning animals to air after prior oxygen exposure reduced the number of survivors past 10 hours and shortened the maximum survival in those groups. These features indicate the development of a dependency of the defense mechanisms on the availability of oxygen at the higher level for metabolic and possibly other aspects of the pulmonary and systemic response to injury, beyond the usual physiological need. Subset analysis revealed additive and latent effects of oxygen and demonstrated a remarkable rapidity in onset of severe lesions under some circumstances, illustrating the toxicity of oxygen per se.John A. Hartford Foundation, New York, N.Y. 10022-171

    PS Integrins and Laminins: Key Regulators of Cell Migration during Drosophila Embryogenesis

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    During embryonic development, there are numerous cases where organ or tissue formation depends upon the migration of primordial cells. In the Drosophila embryo, the visceral mesoderm (vm) acts as a substrate for the migration of several cell populations of epithelial origin, including the endoderm, the trachea and the salivary glands. These migratory processes require both integrins and laminins. The current model is that αPS1βPS (PS1) and/or αPS3βPS (PS3) integrins are required in migrating cells, whereas αPS2βPS (PS2) integrin is required in the vm, where it performs an as yet unidentified function. Here, we show that PS1 integrins are also required for the migration over the vm of cells of mesodermal origin, the caudal visceral mesoderm (CVM). These results support a model in which PS1 might have evolved to acquire the migratory function of integrins, irrespective of the origin of the tissue. This integrin function is highly specific and its specificity resides mainly in the extracellular domain. In addition, we have identified the Laminin α1,2 trimer, as the key extracellular matrix (ECM) component regulating CVM migration. Furthermore, we show that, as it is the case in vertebrates, integrins, and specifically PS2, contributes to CVM movement by participating in the correct assembly of the ECM that serves as tracks for migration

    Lead Exposures in U.S. Children, 2008: Implications for Prevention

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    The positioning system of the ANTARES Neutrino Telescope

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    The ANTARES neutrino telescope, located 40km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary particles (typically muons) coming from neutrino interactions. As these lines are flexible structures fixed to the sea bed and held taut by a buoy, sea currents cause the lines to move and the storeys to rotate. The knowledge of the position of the optical modules with a precision better than 10cm is essential for a good reconstruction of particle tracks. In this paper the ANTARES positioning system is described. It consists of an acoustic positioning system, for distance triangulation, and a compass-tiltmeter system, for the measurement of the orientation and inclination of the storeys. Necessary corrections are discussed and the results of the detector alignment procedure are described

    Utilizing the chicken as an animal model for human craniofacial ciliopathies

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    The chicken has been a particularly useful model for the study of craniofacial development and disease for over a century due to their relatively large size, accessibility, and amenability for classical bead implantation and transplant experiments. Several naturally occurring mutant lines with craniofacial anomalies also exist and have been heavily utilized by developmental biologist for several decades. Two of the most well known lines, talpid(2) (ta(2)) and talpid(3) (ta(3)), represent the first spontaneous mutants to have the causative genes identified. Despite having distinct genetic causes, both mutants have recently been identified as ciliopathic. Excitingly, both of these mutants have been classified as models for human craniofacial ciliopathies: Oral-facial-digital syndrome (ta(2)) and Joubert syndrome (ta(3)). Herein, we review and compare these two models of craniofacial disease and highlight what they have revealed about the molecular and cellular etiology of ciliopathies. Furthermore, we outline how applying classical avian experiments and new technological advances (transgenics and genome editing) with naturally occurring avian mutants can add a tremendous amount to what we currently know about craniofacial ciliopathies

    SOSORT consensus paper: school screening for scoliosis. Where are we today?

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    This report is the SOSORT Consensus Paper on School Screening for Scoliosis discussed at the 4th International Conference on Conservative Management of Spinal Deformities, presented by SOSORT, on May 2007. The objectives were numerous, 1) the inclusion of the existing information on the issue, 2) the analysis and discussion of the responses by the meeting attendees to the twenty six questions of the questionnaire, 3) the impact of screening on frequency of surgical treatment and of its discontinuation, 4) the reasons why these programs must be continued, 5) the evolving aim of School Screening for Scoliosis and 6) recommendations for improvement of the procedure
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