77 research outputs found
Innate Immune Sensing of DNA
Discusses efforts to understand how DNA triggers immune responses
PET/CT Imaging of c-Myc Transgenic Mice Identifies the Genotoxic N-Nitroso-Diethylamine as Carcinogen in a Short-Term Cancer Bioassay
Background: More than 100,000 chemicals are in use but have not been tested for their safety. To overcome limitations in the cancer bioassay several alternative testing strategies are explored. The inability to monitor non-invasively onset and progression of disease limits, however, the value of current testing strategies. Here, we report the application of in vivo imaging to a c-Myc transgenic mouse model of liver cancer for the development of a short-term cancer bioassay. Methodology/Principal Findings: mCT and 18 F-FDG mPET were used to detect and quantify tumor lesions after treatment with the genotoxic carcinogen NDEA, the tumor promoting agent BHT or the hepatotoxin paracetamol. Tumor growth was investigated between the ages of 4 to 8.5 months and contrast-enhanced mCT imaging detected liver lesions as well as metastatic spread with high sensitivity and accuracy as confirmed by histopathology. Significant differences in the onset of tumor growth, tumor load and glucose metabolism were observed when the NDEA treatment group was compared with any of the other treatment groups. NDEA treatment of c-Myc transgenic mice significantly accelerated tumor growth and caused metastatic spread of HCC in to lung but this treatment also induced primary lung cancer growth. In contrast, BHT and paracetamol did not promote hepatocarcinogenesis. Conclusions/Significance: The present study evidences the accuracy of in vivo imaging in defining tumor growth, tumor load, lesion number and metastatic spread. Consequently, the application of in vivo imaging techniques to transgeni
A protein methylation pathway in Chlamydomonas flagella is active during flagellar resorption
Author Posting. Β© American Society for Cell Biology, 2008. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 19 (2008): 4319-4327, doi:10.1091/mbc.E08-05-0470.During intraflagellar transport (IFT), the regulation of motor proteins, the loading and unloading of cargo and the turnover of flagellar proteins all occur at the flagellar tip. To begin an analysis of the protein composition of the flagellar tip, we used difference gel electrophoresis to compare long versus short (i.e., regenerating) flagella. The concentration of tip proteins should be higher relative to that of tubulin (which is constant per unit length of the flagellum) in short compared with long flagella. One protein we have identified is the cobalamin-independent form of methionine synthase (MetE). Antibodies to MetE label flagella in a punctate pattern reminiscent of IFT particle staining, and immunoblot analysis reveals that the amount of MetE in flagella is low in full-length flagella, increased in regenerating flagella, and highest in resorbing flagella. Four methylated proteins have been identified in resorbing flagella, using antibodies specific for asymmetrically dimethylated arginine residues. These proteins are found almost exclusively in the axonemal fraction, and the methylated forms of these proteins are essentially absent in full-length and regenerating flagella. Because most cells resorb cilia/flagella before cell division, these data indicate a link between flagellar protein methylation and progression through the cell cycle.This work was supported by National Institutes
of Health Grant DK071720 (R.D.S.) and National Science Foundation Grant
MCB 0418877 (R.D.S.)
The Systemic Assessment Clinic, a novel method for assessing patients in general adult psychiatry: Presentation and preliminary service evaluation
The traditional model of psychiatric assessment and diagnosis can be criticised as reductive. We developed an innovative model for psychiatric assessment of adult patients referred to our adult mental health team, the Systemic Assessment Clinic, incorporating the principles and techniques of systemic family therapy and dialogical practice into standard psychiatric assessment. We conducted a service evaluation, comparing prospective use of mental health services for patients assessed either in the Systemic Assessment Clinic or in standard assessment. Patients assessed in the Systemic Assessment Clinic had more favourable outcomes than those in standard assessment: they were significantly less likely to need multiple follow-up treatment appointments with a psychiatrist and to be re-referred to mental health services once discharged, indicating reduced healthcare costs. Satisfaction rates for participants attending the systemic assessment clinic were high. Our service evaluation gives preliminary evidence that the Systemic Assessment Clinic could be a potential new model for psychiatric assessment; further evaluation is warranted in a randomised controlled trial
Field Attractants for Pachnoda interrupta Selected by Means of GC-EAD and Single Sensillum Screening
The sorghum chafer, Pachnoda interrupta Olivier (Coleoptera: Scarabaeidae: Cetoniinae), is a key pest on sorghum, Sorghum bicolor (L.) Moench (Poaceae), in Ethiopia. At present there is a lack of efficient control methods. Trapping shows promise for reduction of the pest population, but would benefit from the development of attractive lures. To find attractants that could be used for control of P. interrupta, either by mass trapping or by monitoring as part of integrated pest management, we screened headspace collections of sorghum and the highly attractive weed Abutilon figarianum Webb (Malvaceae) for antennal activity using gas chromatograph-coupled electroantennographic detection (GC-EAD). Compounds active in GC-EAD were identified by combined gas chromatography and mass spectrometry (GC-MS). Field trapping suggested that attraction is governed by a few influential compounds, rather than specific odor blends. Synthetic sorghum and abutilon odor blends were attractive, but neither blend outperformed the previously tested attractants eugenol and methyl salicylate, of which the latter also was part of the abutilon blend. The strong influence of single compounds led us to search for novel attractive compounds, and to investigate the role of individual olfactory receptor neurons (ORNs) in the perception of kairomones. We screened the response characteristics of ORNs to 82 putative kairomones in single sensillum recordings (SSR), and found a number of key ligand candidates for specific classes of ORNs. Out of these key ligand candidates, six previously untested compounds were selected for field trapping trials: anethole, benzaldehyde, racemic 2,3-butanediol, isoamyl alcohol, methyl benzoate and methyl octanoate. The compounds were selected on the basis that they activated different classes of ORNs, thus allowing us to test potential kairomones that activate large non-overlapping populations of the peripheral olfactory system, while avoiding redundant multiple activations of the same ORN type. Field trapping results revealed that racemic 2,3-butanediol is a powerful novel attractant for P. interrupta
Generation of a Convalescent Model of Virulent Francisella tularensis Infection for Assessment of Host Requirements for Survival of Tularemia
Francisella tularensis is a facultative intracellular bacterium and the causative agent of tularemia. Development of novel vaccines and therapeutics for tularemia has been hampered by the lack of understanding of which immune components are required to survive infection. Defining these requirements for protection against virulent F. tularensis, such as strain SchuS4, has been difficult since experimentally infected animals typically die within 5 days after exposure to as few as 10 bacteria. Such a short mean time to death typically precludes development, and therefore assessment, of immune responses directed against virulent F. tularensis. To enable identification of the components of the immune system that are required for survival of virulent F. tularensis, we developed a convalescent model of tularemia in C57Bl/6 mice using low dose antibiotic therapy in which the host immune response is ultimately responsible for clearance of the bacterium. Using this model we demonstrate Ξ±Ξ²TCR+ cells, Ξ³Ξ΄TCR+ cells, and B cells are necessary to survive primary SchuS4 infection. Analysis of mice deficient in specific soluble mediators shows that IL-12p40 and IL-12p35 are essential for survival of SchuS4 infection. We also show that IFN-Ξ³ is required for survival of SchuS4 infection since mice lacking IFN-Ξ³R succumb to disease during the course of antibiotic therapy. Finally, we found that both CD4+ and CD8+ cells are the primary producers of IFN-Ξ³and that Ξ³Ξ΄TCR+ cells and NK cells make a minimal contribution toward production of this cytokine throughout infection. Together these data provide a novel model that identifies key cells and cytokines required for survival or exacerbation of infection with virulent F. tularensis and provides evidence that this model will be a useful tool for better understanding the dynamics of tularemia infection
Generating dialogical practices in mental health : experiences from southern Norway, 1998-2008
Published version of an article in the journal: Administration and Policy in Mental Health and Mental Health Services Research. Also available from the publisher at: http://dx.doi.org/10.1007/s10488-013-0479-3In Norway and many other countries, political guidelines prescribe the development of mental health strategies with both a service user's perspective and a treatment system established by the local authority. The development of new strategies frequently involves challenges regarding procedures and treatment as well as a view of knowledge and humanity. Dialogical practices might provide a solution for these challenges not only because of its procedures but also due to its attitudes toward service users. The aim is to explore the implementation of three dialogical practice programs in Southern Norway from 1998 to 2008 and to critically analyze and discuss the authors' experiences during the implementation process. Three different programs of dialogical practices were initiated, established, and evaluated within the framework of participatory action research. Sustainable changes succeed individually and organizationally when all participants engage as partners during the implementation of new mental health practices. Generating dialogic practice requires shared understanding of the Open Dialogue Approach (ODA) and collaboration between professional networks and among the leaders. Developing a collaboration area that includes service users in all stages of the projects was one of the essential implementation factors. Other factors involved a common vision of ODA by the leaders and the actors, similar experiences, and a culture of collaboration. However, ODA challenged traditional medical therapy and encountered obstacles to collaboration. Perhaps the best way of surmounting those obstacles is to practice ODA itself during the implementation process
TREM2-mediated early microglial response limits diffusion and toxicity of amyloid plaques
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