1,938 research outputs found

    3D Analysis of chromosome architecture: advantages and limitations with SEM

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    Three-dimensional mitotic plant chromosome architecture can be investigated with the highest resolution with scanning electron microscopy compared to other microscopic techniques at present. Specific chromatin staining techniques making use of simultaneous detection of back-scattered electrons and secondary electrons have provided conclusive information on the distribution of DNA and protein in barley chromosomes through mitosis. Applied to investigate the structural effects of different preparative procedures, these techniques were the groundwork for the ``dynamic matrix model{''} for chromosome condensation, which postulates an energy-dependent process of looping and bunching of chromatin coupled with attachment to a dynamic matrix of associated protein fibers. Data from SEM analysis shows basic higher order chromatin structures: chromomeres and matrix fibers. Visualization of nanogold-labeled phosphorylated histone H3 (ser10) with high resolution on chromomeres shows that functional modifications of chromatin can be located on structural elements in a 3D context. Copyright (C) 2005 S. Karger AG, Basel

    Fibrosis in the kidney: is a problem shared a problem halved?

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    Fibrotic disorders are commonplace, take many forms and can be life-threatening. No better example of this exists than the progressive fibrosis that accompanies all chronic renal disease. Renal fibrosis is a direct consequence of the kidney's limited capacity to regenerate after injury. Renal scarring results in a progressive loss of renal function, ultimately leading to end-stage renal failure and a requirement for dialysis or kidney transplantation

    道徳と幸福 : カント倫理思想の一考察

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    Asthma is a serious health problem and during the last decade various experimental models of asthma have been developed to study the pathogenesis of this disease. In this study we describe a new mouse model of asthma that uses the spores of Alternaria alternata and Cladosporium herbarum, two allergenic molds recognized as common inducers of rhinitis and asthma in humans. Here we demonstrate that A. alternata and C. herbarum spores are immunogenic when injected into BALB/c mice, and induce the production of specific IgM and IgG1 antibodies and strongly increase IgE serum levels. To induce the allergic response, mice were sensitized by two intraperitoneal (i.p.) injections and then intranasaly (i.n.) challenged with A. alternata and C. herbarum spores. Bronchoalveolar lavages (BALs) from these mice contained numerous macrophages, neutrophils, eosinophils and lymphocytes whereas neutrophils were the predominant BAL inflammatory cells in nonsensitized mice. Histological studies demonstrated an influx of eosinophils in peri-vascular and peri-bronchial areas and the presence of numerous epithelial goblet cells only in sensitized mice. Increased expression of mRNA specific for various chemokines (eotaxin, MIP-1α, MIP-2) and chemokine receptors (CCR-1, CCR-2 and CCR-5) was observed in the lungs of nonsensitized mice challenged with the spores. Expression of CCR-3 mRNA in the lungs and Th2 cytokine (IL-4, IL-5 and IL-13) secretion in the BAL was additionally observed in sensitized and challenged mice. Finally we demonstrate through whole-body plethysmography that mold spore sensitization and challenge induce the development of an airway hyperreactivity in response to nebulized methacholine

    Perceptual Other-Race Training Reduces Implicit Racial Bias

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    Background: Implicit racial bias denotes socio-cognitive attitudes towards other-race groups that are exempt from conscious awareness. In parallel, other-race faces are more difficult to differentiate relative to own-race faces – the ‘‘Other-Race Effect.’ ’ To examine the relationship between these two biases, we trained Caucasian subjects to better individuate other-race faces and measured implicit racial bias for those faces both before and after training. Methodology/Principal Findings: Two groups of Caucasian subjects were exposed equally to the same African American faces in a training protocol run over 5 sessions. In the individuation condition, subjects learned to discriminate between African American faces. In the categorization condition, subjects learned to categorize faces as African American or not. For both conditions, both pre- and post-training we measured the Other-Race Effect using old-new recognition and implicit racial biases using a novel implicit social measure – the ‘‘Affective Lexical Priming Score’ ’ (ALPS). Subjects in the individuation condition, but not in the categorization condition, showed improved discrimination of African American faces with training. Concomitantly, subjects in the individuation condition, but not the categorization condition, showed a reduction in their ALPS. Critically, for the individuation condition only, the degree to which an individual subject’s ALPS decreased was significantly correlated with the degree of improvement that subject showed in their ability to differentiate African American faces

    The primary therapy chosen for patients with localized prostate cancer between the university hospital and its affiliated hospitals in Nara Uro-oncological research group registration

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    <p>Abstract</p> <p>Background</p> <p>We investigated the differences between the preferential primary therapy conceived by the primary doctors and the primary therapy actually conducted for prostate cancer patients in Nara, Japan.</p> <p>Methods</p> <p>The distribution of primary therapy and clinical characteristics of 2303 prostate cancer patients - diagnosed between 2004 and 2006 at Nara Medical University and its 23 affiliated hospitals - were assessed. Moreover, the preferential primary therapy for the patients at each clinical stage (cT1-T3bN0M0) conceived by the primary doctors was investigated and compared to the actual therapy.</p> <p>Results</p> <p>Of all patients, 51% received primary androgen deprivation therapy (PADT), 30% underwent radical prostatectomy (RP), and 14% received radiation therapy (RT). The preferential primary therapy for cT1-2N0M0 was RP (92%) while 38% of the patients actually received PADT (RP: 40%). For cT3aN0M0, the preferential primary therapy was both RP and external beam radiation therapy (EBRT) while 58% of the patients actually received PADT (RP: 16%, EBRT: 24%). For cT3bN0M0, the most preferential primary therapy was EBRT (46%) while 67% of the patients actually received PADT (EBRT: 21%). This trend was more notable in the affiliated hospitals than in the University hospital. The hospitals with lower volume of RP per year significantly conducted PADT compared with those with higher volume of RP.</p> <p>Conclusions</p> <p>PADT was commonly used to treat localized prostate cancer as well as locally advanced prostate cancer in Japan. There was a definite discrepancy between the preferential primary therapy conceived by the primary doctors and the actual therapy provided to the patients.</p

    Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

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    We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al

    Multiple Regulatory Mechanisms to Inhibit Untimely Initiation of DNA Replication Are Important for Stable Genome Maintenance

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    Genomic instability is a hallmark of human cancer cells. To prevent genomic instability, chromosomal DNA is faithfully duplicated in every cell division cycle, and eukaryotic cells have complex regulatory mechanisms to achieve this goal. Here, we show that untimely activation of replication origins during the G1 phase is genotoxic and induces genomic instability in the budding yeast Saccharomyces cerevisiae. Our data indicate that cells preserve a low level of the initiation factor Sld2 to prevent untimely initiation during the normal cell cycle in addition to controlling the phosphorylation of Sld2 and Sld3 by cyclin-dependent kinase. Although untimely activation of origin is inhibited on multiple levels, we show that deregulation of a single pathway can cause genomic instability, such as gross chromosome rearrangements (GCRs). Furthermore, simultaneous deregulation of multiple pathways causes an even more severe phenotype. These findings highlight the importance of having multiple inhibitory mechanisms to prevent the untimely initiation of chromosome replication to preserve stable genome maintenance over generations in eukaryotes
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