871 research outputs found

    A Method to Quantify Mouse Coat-Color Proportions

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    Coat-color proportions and patterns in mice are used as assays for many processes such as transgene expression, chimerism, and epigenetics. In many studies, coat-color readouts are estimated from subjective scoring of individual mice. Here we show a method by which mouse coat color is quantified as the proportion of coat shown in one or more digital images. We use the yellow-agouti mouse model of epigenetic variegation to demonstrate this method. We apply this method to live mice using a conventional digital camera for data collection. We use a raster graphics editing program to convert agouti regions of the coat to a standard, uniform, brown color and the yellow regions of the coat to a standard, uniform, yellow color. We use a second program to quantify the proportions of these standard colors. This method provides quantification that relates directly to the visual appearance of the live animal. It also provides an objective analysis with a traceable record, and it should allow for precise comparisons of mouse coats and mouse cohorts within and between studies

    Gross-Neveu Models, Nonlinear Dirac Equations, Surfaces and Strings

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    Recent studies of the thermodynamic phase diagrams of the Gross-Neveu model (GN2), and its chiral cousin, the NJL2 model, have shown that there are phases with inhomogeneous crystalline condensates. These (static) condensates can be found analytically because the relevant Hartree-Fock and gap equations can be reduced to the nonlinear Schr\"odinger equation, whose deformations are governed by the mKdV and AKNS integrable hierarchies, respectively. Recently, Thies et al have shown that time-dependent Hartree-Fock solutions describing baryon scattering in the massless GN2 model satisfy the Sinh-Gordon equation, and can be mapped directly to classical string solutions in AdS3. Here we propose a geometric perspective for this result, based on the generalized Weierstrass spinor representation for the embedding of 2d surfaces into 3d spaces, which explains why these well-known integrable systems underlie these various Gross-Neveu gap equations, and why there should be a connection to classical string theory solutions. This geometric viewpoint may be useful for higher dimensional models, where the relevant integrable hierarchies include the Davey-Stewartson and Novikov-Veselov systems.Comment: 27 pages, 1 figur

    Detecting Latin-Based Medical Terminology in Croatian Texts

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    No matter what the main language of texts in the medical domain is, there is always an evidence of the usage of Latin-derived words and formative elements in terminology development. Generally speaking, this usage presents language-specific morpho-semantic behaviors in forming both technical-scientific and common-usage words. Nevertheless, this usage of Latin in Croatian medical texts does not seem consistent due to the fact that diferent mechanisms of word formation may be applied to the same term. In our pursuit to map all the diferent occurrences of the same concept to only one, we propose a model designed within NooJ and based on dictionaries and morphological grammars. Starting from the manual detection of nouns and their variations, we recognize some word formation mechanisms and develop grammars suitable to recognize Latinisms and Croatinized Latin medical terminology

    Cellular Radiosensitivity: How much better do we understand it?

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    Purpose: Ionizing radiation exposure gives rise to a variety of lesions in DNA that result in genetic instability and potentially tumorigenesis or cell death. Radiation extends its effects on DNA by direct interaction or by radiolysis of H2O that generates free radicals or aqueous electrons capable of interacting with and causing indirect damage to DNA. While the various lesions arising in DNA after radiation exposure can contribute to the mutagenising effects of this agent, the potentially most damaging lesion is the DNA double strand break (DSB) that contributes to genome instability and/or cell death. Thus in many cases failure to recognise and/or repair this lesion determines the radiosensitivity status of the cell. DNA repair mechanisms including homologous recombination (HR) and non-homologous end-joining (NHEJ) have evolved to protect cells against DNA DSB. Mutations in proteins that constitute these repair pathways are characterised by radiosensitivity and genome instability. Defects in a number of these proteins also give rise to genetic disorders that feature not only genetic instability but also immunodeficiency, cancer predisposition, neurodegeneration and other pathologies. Conclusions: In the past fifty years our understanding of the cellular response to radiation damage has advanced enormously with insight being gained from a wide range of approaches extending from more basic early studies to the sophisticated approaches used today. In this review we discuss our current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempt to provide an explanation for what it is that determines the response to radiation

    Endocytosis of DNA-Hsp65 Alters the pH of the Late Endosome/Lysosome and Interferes with Antigen Presentation

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    BACKGROUND: Experimental models using DNA vaccine has shown that this vaccine is efficient in generating humoral and cellular immune responses to a wide variety of DNA-derived antigens. Despite the progress in DNA vaccine development, the intracellular transport and fate of naked plasmid DNA in eukaryotic cells is poorly understood, and need to be clarified in order to facilitate the development of novel vectors and vaccine strategies. METHODOLOGY AND PRINCIPAL FINDINGS: Using confocal microscopy, we have demonstrated for the first time that after plasmid DNA uptake an inhibition of the acidification of the lysosomal compartment occurs. This lack of acidification impaired antigen presentation to CD4 T cells, but did not alter the recruitment of MyD88. The recruitment of Rab 5 and Lamp I were also altered since we were not able to co-localize plasmid DNA with Rab 5 and Lamp I in early endosomes and late endosomes/lysosomes, respectively. Furthermore, we observed that the DNA capture process in macrophages was by clathrin-mediated endocytosis. In addition, we observed that plasmid DNA remains in vesicles until it is in a juxtanuclear location, suggesting that the plasmid does not escape into the cytoplasmic compartment. CONCLUSIONS AND SIGNIFICANCE: Taken together our data suggests a novel mechanism involved in the intracellular trafficking of plasmid DNA, and opens new possibilities for the use of lower doses of plasmid DNA to regulate the immune response

    Randomised controlled trial of a theoretically grounded tailored intervention to diffuse evidence-based public health practice [ISRCTN23257060]

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    BACKGROUND: Previous studies have shown that Norwegian public health physicians do not systematically and explicitly use scientific evidence in their practice. They work in an environment that does not encourage the integration of this information in decision-making. In this study we investigate whether a theoretically grounded tailored intervention to diffuse evidence-based public health practice increases the physicians' use of research information. METHODS: 148 self-selected public health physicians were randomised to an intervention group (n = 73) and a control group (n = 75). The intervention group received a multifaceted intervention while the control group received a letter declaring that they had access to library services. Baseline assessments before the intervention and post-testing immediately at the end of a 1.5-year intervention period were conducted. The intervention was theoretically based and consisted of a workshop in evidence-based public health, a newsletter, access to a specially designed information service, to relevant databases, and to an electronic discussion list. The main outcome measure was behaviour as measured by the use of research in different documents. RESULTS: The intervention did not demonstrate any evidence of effects on the objective behaviour outcomes. We found, however, a statistical significant difference between the two groups for both knowledge scores: Mean difference of 0.4 (95% CI: 0.2–0.6) in the score for knowledge about EBM-resources and mean difference of 0.2 (95% CI: 0.0–0.3) in the score for conceptual knowledge of importance for critical appraisal. There were no statistical significant differences in attitude-, self-efficacy-, decision-to-adopt- or job-satisfaction scales. There were no significant differences in Cochrane library searching after controlling for baseline values and characteristics. CONCLUSION: Though demonstrating effect on knowledge the study failed to provide support for the hypothesis that a theory-based multifaceted intervention targeted at identified barriers will change professional behaviour

    High-Resolution Melting Analysis as a Powerful Tool to Discriminate and Genotype Pseudomonas savastanoi Pathovars and Strains

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    Pseudomonas savastanoi is a serious pathogen of Olive, Oleander, Ash, and several other Oleaceae. Its epiphytic or endophytic presence in asymptomatic plants is crucial for the spread of Olive and Oleander knot disease, as already ascertained for P. savastanoi pv. savastanoi (Psv) on Olive and for pv. nerii (Psn) on Oleander, while no information is available for pv. fraxini (Psf) on Ash. Nothing is known yet about the distribution on the different host plants and the real host range of these pathovars in nature, although cross-infections were observed following artificial inoculations. A multiplex Real-Time PCR assay was recently developed to simultaneously and quantitatively discriminate in vitro and in planta these P. savastanoi pathovars, for routine culture confirmation and for epidemiological and diagnostical studies. Here an innovative High-Resolution Melting Analysis (HRMA)-based assay was set up to unequivocally discriminate Psv, Psn and Psf, according to several single nucleotide polymorphisms found in their Type Three Secretion System clusters. The genetic distances among 56 P. savastanoi strains belonging to these pathovars were also evaluated, confirming and refining data previously obtained by fAFLP. To our knowledge, this is the first time that HRMA is applied to a bacterial plant pathogen, and one of the few multiplex HRMA-based assays developed so far. This protocol provides a rapid, sensitive, specific tool to differentiate and detect Psv, Psn and Psf strains, also in vivo and against other related bacteria, with lower costs than conventional multiplex Real-Time PCR. Its application is particularly suitable for sanitary certification programs for P. savastanoi, aimed at avoiding the spreading of this phytopathogen through asymptomatic plants

    A Drastic Reduction in the Life Span of Cystatin C L68Q Carriers Due to Life-Style Changes during the Last Two Centuries

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    Hereditary cystatin C amyloid angiopathy (HCCAA) is an autosomal dominant disease with high penetrance, manifest by brain hemorrhages in young normotensive adults. In Iceland, this condition is caused by the L68Q mutation in the cystatin C gene, with contemporary carriers reaching an average age of only 30 years. Here, we report, based both on linkage disequilibrium and genealogical evidence, that all known copies of this mutation derive from a common ancestor born roughly 18 generations ago. Intriguingly, the genealogies reveal that obligate L68Q carriers born 1825 to 1900 experienced a drastic reduction in life span, from 65 years to the present-day average. At the same time, a parent-of-origin effect emerged, whereby maternal inheritance of the mutation was associated with a 9 year reduction in life span relative to paternal inheritance. As these trends can be observed in several different extended families, many generations after the mutational event, it seems likely that some environmental factor is responsible, perhaps linked to radical changes in the life-style of Icelanders during this period. A mutation with such radically different phenotypic effects in reaction to normal variation in human life-style not only opens the possibility of preventive strategies for HCCAA, but it may also provide novel insights into the complex relationship between genotype and environment in human disease

    Differential Requirement for Utrophin in the Induced Pluripotent Stem Cell Correction of Muscle versus Fat in Muscular Dystrophy Mice

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    Duchenne muscular dystrophy (DMD) is an incurable degenerative muscle disorder. We injected WT mouse induced pluripotent stem cells (iPSCs) into mdx and mdx∶utrophin mutant blastocysts, which are predisposed to develop DMD with an increasing degree of severity (mdx <<< mdx∶utrophin). In mdx chimeras, iPSC-dystrophin was supplied to the muscle sarcolemma to effect corrections at morphological and functional levels. Dystrobrevin was observed in dystrophin-positive and, at a lesser extent, utrophin-positive areas. In the mdx∶utrophin mutant chimeras, although iPSC-dystrophin was also supplied to the muscle sarcolemma, mice still displayed poor skeletal muscle histopathology, and negligible levels of dystrobrevin in dystrophin- and utrophin-negative areas. Not only dystrophin-expressing tissues are affected by iPSCs. Mdx and mdx∶utrophin mice have reduced fat/body weight ratio, but iPSC injection normalized this parameter in both mdx and mdx∶utrophin chimeras, despite the fact that utrophin was compromised in the mdx∶utrophin chimeric fat. The results suggest that the presence of utrophin is required for the iPSC-corrections in skeletal muscle. Furthermore, the results highlight a potential (utrophin-independent) non-cell autonomous role for iPSC-dystrophin in the corrections of non-muscle tissue like fat, which is intimately related to the muscle

    The HOPE fixation technique - a promising alternative to common prostate cancer biobanking approaches

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    <p>Abstract</p> <p>Background</p> <p>The availability of well-annotated prostate tissue samples through biobanks is key for research. Whereas fresh-frozen tissue is well suited for a broad spectrum of molecular analyses, its storage and handling is complex and cost-intensive. Formalin-fixed paraffin-embedded specimens (FFPE) are easy to handle and economic to store, but their applicability for molecular methods is restricted. The recently introduced Hepes-glutamic acid-buffer mediated Organic solvent Protection Effect (HOPE) is a promising alternative, which might have the potential to unite the benefits of FFPE and fresh-frozen specimen. Aim of the study was to compare HOPE-fixed, FFPE and fresh-frozen bio-specimens for their accessibility for diagnostic and research purposes.</p> <p>Methods</p> <p>10 prostate cancer samples were each preserved with HOPE, formalin, and liquid nitrogen and studied with in-situ and molecular methods. Samples were H&E stained, and assessed by immunohistochemistry (i.e. PSA, GOLPH2, p63) and FISH (i.e. <it>ERG </it>rearrangement). We assessed DNA integrity by PCR, using control genes ranging from 100 to 600 bp amplicon size. RNA integrity was assessed through qRT-PCR on three housekeeping genes (TBP, GAPDH, β-actin). Protein expression was analysed by performing western blot analysis using GOLPH2 and PSA antibodies.</p> <p>Results</p> <p>Of the HOPE samples, morphologic quality of H&E sections, immunohistochemical staining, and the FISH assay was at least equal to FFPE tissue, and significantly better than the fresh-frozen specimens. DNA, RNA, and protein analysis of HOPE samples provided similar results as compared to fresh-frozen specimens. As expected, FFPE-samples were inferior for most of the molecular analyses.</p> <p>Conclusions</p> <p>This is the first study, comparatively assessing the suitability of these fixation methods for diagnostic and research utilization. Overall, HOPE-fixed bio-specimens combine the benefits of FFPE- and fresh-frozen samples. Results of this study have the potential to expand on contemporary prostate tissue biobanking approaches and can serve as a model for other organs and tumors.</p
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