379 research outputs found

    Are reviewers suggested by authors as good as those chosen by editors? Results of a rater-blinded, retrospective study

    Get PDF
    BACKGROUND: BioMed Central (BMC) requires authors to suggest four reviewers when making a submission. Editors searching for reviewers use these suggestions as a source. The review process of the medical journals in the BMC series is open – authors and reviewers know each other's identity – although reviewers can make confidential comments to the editor. Reviews are published alongside accepted articles so readers may see the reviewers' names and recommendations. Our objective was to compare the performance of author-nominated reviewers (ANR) with that of editor-chosen reviewers (ECR) in terms of review quality and recommendations about submissions in an online-only medical journal. METHODS: Pairs of reviews from 100 consecutive submissions to medical journals in the BMC series (with one author-nominated and one editor-chosen reviewer and a final decision) were assessed by two raters, blinded to reviewer type, using a validated review quality instrument (RQI) which rates 7 items on 5-point Likert scales. The raters discussed their ratings after the first 20 pairs (keeping reviewer type masked) and resolved major discrepancies in scoring and interpretation to improve inter-rater reliability. Reviewers' recommendations were also compared. RESULTS: Reviewer source had no impact on review quality (mean RQI score (± SD) 2.24 ± 0.55 for ANR, 2.34 ± 0.54 for ECR) or tone (mean scores on additional question 2.72 ANR vs 2.82 ECR) (maximum score = 5 in both cases). However author-nominated reviewers were significantly more likely to recommend acceptance (47 vs 35) and less likely to recommend rejection (10 vs 23) than editor-chosen reviewers after initial review (p < 0.001). However, by the final review stage (i.e. after authors had responded to reviewer comments) ANR and ECR recommendations were similar (65 vs 66 accept, 10 vs 14 reject, p = 0.47). The number of reviewers unable to decide about acceptance was similar in both groups at both review stages. CONCLUSION: Author-nominated reviewers produced reviews of similar quality to editor-chosen reviewers but were more likely to recommend acceptance during the initial stages of peer review

    Telomere disruption results in non-random formation of de novo dicentric chromosomes involving acrocentric human chromosomes

    Get PDF
    Copyright: © 2010 Stimpson et al.Genome rearrangement often produces chromosomes with two centromeres (dicentrics) that are inherently unstable because of bridge formation and breakage during cell division. However, mammalian dicentrics, and particularly those in humans, can be quite stable, usually because one centromere is functionally silenced. Molecular mechanisms of centromere inactivation are poorly understood since there are few systems to experimentally create dicentric human chromosomes. Here, we describe a human cell culture model that enriches for de novo dicentrics. We demonstrate that transient disruption of human telomere structure non-randomly produces dicentric fusions involving acrocentric chromosomes. The induced dicentrics vary in structure near fusion breakpoints and like naturally-occurring dicentrics, exhibit various inter-centromeric distances. Many functional dicentrics persist for months after formation. Even those with distantly spaced centromeres remain functionally dicentric for 20 cell generations. Other dicentrics within the population reflect centromere inactivation. In some cases, centromere inactivation occurs by an apparently epigenetic mechanism. In other dicentrics, the size of the alpha-satellite DNA array associated with CENP-A is reduced compared to the same array before dicentric formation. Extrachromosomal fragments that contained CENP-A often appear in the same cells as dicentrics. Some of these fragments are derived from the same alpha-satellite DNA array as inactivated centromeres. Our results indicate that dicentric human chromosomes undergo alternative fates after formation. Many retain two active centromeres and are stable through multiple cell divisions. Others undergo centromere inactivation. This event occurs within a broad temporal window and can involve deletion of chromatin that marks the locus as a site for CENP-A maintenance/replenishment.This work was supported by the Tumorzentrum Heidelberg/Mannheim grant (D.10026941)and by March of Dimes Research Foundation grant #1-FY06-377 and NIH R01 GM069514

    Different osteosyntheses for Colles' fracture: A mechanical study in 42 cadaver bones

    Get PDF
    Background and purpose In recent years several different plate designs for internal fixation of fractures of the distal radius have been developed. However, few biomechanical studies have been performed to compare these new implants. The purpose of this study was to compare the mechanical properties of 5 different commercially available plates (3 volar and 2 dorsal) with standard K-wire fixation using a distal radial cadaver model

    Using human artificial chromosomes to study centromere assembly and function

    Get PDF

    Patient's needs and preferences in routine follow-up after treatment for breast cancer

    Get PDF
    The purpose of the study was to analyse the needs of women who participated in a routine follow-up programme after treatment for primary breast cancer. A cross-sectional survey was conducted using a postal questionnaire among women without any sign of relapse during the routine follow-up period. The questionnaire was sent 2-4 years after primary surgical treatment. Most important to patients was information on long-term effects of treatment and prognosis, discussion of prevention of breast cancer and hereditary factors and changes in the untreated breast. Patients preferred additional investigations (such as X-ray and blood tests) to be part of routine follow-up visits. Less satisfaction with interpersonal aspects and higher scores on the Hospital Anxiety and Depression Scale (HADS) scale were related to stronger preferences for additional investigation. Receiving adjuvant hormonal or radiotherapy was related to a preference for a more intensive follow-up schedule. There were no significant differences between patients treated with mastectomy compared to treated with breast-conserving therapy. During routine follow-up after a diagnosis of breast cancer, not all patients needed all types of information. When introducing alternative follow-up schedules, individual patients' information needs and preferences should be identified early and incorporated into the follow-up routine care, to target resources and maximise the likelihood that positive patient outcomes will result

    Protecting a transgene expression from the HAC-based vector by different chromatin insulators

    Get PDF
    Human artificial chromosomes (HACs) are vectors that offer advantages of capacity and stability for gene delivery and expression. Several studies have even demonstrated their use for gene complementation in gene-deficient recipient cell lines and animal transgenesis. Recently, we constructed an advance HAC-based vector, alphoid(tetO)-HAC, with a conditional centromere. In this HAC, a gene-loading site was inserted into a centrochromatin domain critical for kinetochore assembly and maintenance. While by definition this domain is permissive for transcription, there have been no long-term studies on transgene expression within centrochromatin. In this study, we compared the effects of three chromatin insulators, cHS4, gamma-satellite DNA, and tDNA, on the expression of an EGFP transgene inserted into the alphoid(tetO)-HAC vector. Insulator function was essential for stable expression of the transgene in centrochromatin. In two analyzed host cell lines, a tDNA insulator composed of two functional copies of tRNA genes showed the highest barrier activity. We infer that proximity to centrochromatin does not protect genes lacking chromatin insulators from epigenetic silencing. Barrier elements that prevent gene silencing in centrochromatin would thus help to optimize transgenesis using HAC vectors. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00018-013-1362-9) contains supplementary material, which is available to authorized users
    • …
    corecore