44 research outputs found

    Modular Architecture and Unique Teichoic Acid Recognition Features of Choline-Binding Protein L (CbpL) Contributing to Pneumococcal Pathogenesis

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    The human pathogen Streptococcus pneumoniae is decorated with a special class of surface-proteins known as choline-binding proteins (CBPs) attached to phosphorylcholine (PCho) moieties from cell-wall teichoic acids. By a combination of X-ray crystallography, NMR, molecular dynamics techniques and in vivo virulence and phagocytosis studies, we provide structural information of choline-binding protein L (CbpL) and demonstrate its impact on pneumococcal pathogenesis and immune evasion. CbpL is a very elongated three-module protein composed of (i) an Excalibur Ca 2+ -binding domain -reported in this work for the very first time-, (ii) an unprecedented anchorage module showing alternate disposition of canonical and non-canonical choline-binding sites that allows vine-like binding of fully-PCho-substituted teichoic acids (with two choline moieties per unit), and (iii) a Ltp-Lipoprotein domain. Our structural and infection assays indicate an important role of the whole multimodular protein allowing both to locate CbpL at specific places on the cell wall and to interact with host components in order to facilitate pneumococcal lung infection and transmigration from nasopharynx to the lungs and blood. CbpL implication in both resistance against killing by phagocytes and pneumococcal pathogenesis further postulate this surface-protein as relevant among the pathogenic arsenal of the pneumococcus.We gratefully acknowledge Karsta Barnekow and Kristine Sievert-Giermann, for technical assistance and Lothar Petruschka for in silico analysis (all Dept. of Genetics, University of Greifswald). We are further grateful to the staff from SLS synchrotron beamline for help in data collection. This work was supported by grants from the Deutsche Forschungsgemeinschaft DFG GRK 1870 (to SH) and the Spanish Ministry of Economy and Competitiveness (BFU2014-59389-P to JAH, CTQ2014-52633-P to MB and SAF2012-39760-C02-02 to FG) and S2010/BMD- 2457 (Community of Madrid to JAH and FG).Peer Reviewe

    The techno-ecological practice as the politics of ontological coalitions

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    The paper focuses on the art projects aimed at visualizing (grasping) the physical or biological phenomena through interfaces and / or installations designed specifically for such purpose. Such works often mirror the post-­digital condition of our time where the digital technologies constitute the common background for everyday activities, no longer having the allure of "new" and "exciting" (Berry, Dieter et al., 2015). In this process, both the networked technologies of wireless communication and the act of crossing the boundaries between the digital and the physical play the crucial role as the post-­digital networked imagery increasingly becomes directly connected to the physical environment. I would like to ponder on the questions of processuality and relationality involved in such instances where the complexity of the hybrid works of art clearly transgresses the paradigm of representationalism (Thrift, 2008;; Anderson and Harrison, 2010;; Kember and Zylinska, 2012). The particular attention is given to the fact that such artworks bond different ontological realms (discursive, physical, digital) and different agents (human and non-­human, carbon-­based and software-­based) forging “ontological coalitions” (Malafouris, 2013). Throughout the article the mutlirealist and relational perspective is offered, inspired by the propositions of Gilbert Simondon and Etienne Souriau. Based on the research project supported by National Science Centre Poland ("The aesthetics of post-­digital imagery: between new materialism and object-­oriented philosophy", 2016/21/B/HS2/00746)

    Ovarian cancer molecular pathology.

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    Toward conservational anthropology: addressing anthropocentric bias in anthropology

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    Anthropological literature addressing conservation and development often blames 'conservationists' as being neo-imperialist in their attempts to institute limits to commercial activities by imposing their post-materialist eco-ideology. The author argues that this view of conservationists is ironic in light of the fact that the very notion of 'development' is arguably an imposition of the (Western) elites. The anthropocentric bias in anthropology also permeates constructivist ethnographies of human-animal 'interactions,' which tend to emphasize the socio-cultural complexity and interconnectivity rather than the unequal and often extractive nature of this 'interaction.' Anthropocentrism is argued to be counteractive to reconciling conservationists' efforts at environmental protection with the traditional ontologies of the interdependency of human-nature relationship

    Entwicklung einer Pruefmethode und Untersuchungen zur Begrenzung von Emissionen aus Druckern und Kopiergeraeten im Rahmen der Umweltzeichenvergabe

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    The emission behaviour with regard to dust, ozone and VOC (TVOC) of nine different hardcopy devices in combination with suitable air sampling and analysis procedures was investigated in different emission test chambers (two different 1m"3 - chambers and one 20 m"3 -chamber). Air sampling and analysis for VOC were done by means of Tenax TA and subsequent thermal desorption (TDS) in connection with GC/MS. Ozone was determined continuously. The ozone analyser worked on the basis of the flame rid reaction of ozone with ethylene according to the principle of chemiluminescence. The dust determination was done gravimetrically by means of glass fibre filter and an ultra micro-balance. Additional the particle emission during the printing process was measured with a particle counter. The general technical conditions of the tested hardcopy devices were the reason for short printing times with a maximum of 36 minutes. In order to achieve the equilibrium concentration in the test chambers the air exchange rate in the 1 m"3 - test chambers had to be increased to a value of n=4,0 to 4,7 per hour. Additional to the examination of the hardcopy devices in the emission test chambers different papers were investigated by means of direct - TDS and different toners were tested by means of head space sampling in combination with GC/MS. For the examined hardcopy devices emission rates were determined. The emission rates for TVOC ranged from 0,41 to 22,4 mg per piece and hour, for ozone from less than 0,02 to 4,6 mg per piece and hour and for dust from 0,10 to 7,63 mg per piece and hour. The comparison between recycling paper and paper produced form primary fibres showed in general higher SVOC emissions from recycling paper. As the result of the investigations a test method for the determination of emissions from hardcopy devices was developed. This test method is the basis for emission tests in the framework of the German Award of the Environmental Label for office devices RAL-UZ 62, RAL-UZ 85 and the new RAL-UZ 114 for multifunctional devices. (orig.)SIGLEAvailable from TIB Hannover: RN 8422(2003,71) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman

    The chemokine CX3CL1 improves trastuzumab efficacy in HER2 low-expressing cancer in vitro and in vivo.

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    A crucial mode of action of trastuzumab is the labeling of HER2-positive (HER2(+)) tumor cells for the eradication by natural killer (NK) cells, a process called antibody-dependent cellular cytotoxicity (ADCC). However, despite widespread HER2 expression among cancer entities, only a fraction, with robust HER2 overexpression, benefits from trastuzumab therapy. ADCC requires both sufficient lymphocytic infiltration and close binding of the immune cells to the antibody-tagged tumor cells. We hypothesized that the chemokine CX3CL1 could improve both processes, as it is synthesized as a membrane-bound, adhesive form that is eventually cleaved into a soluble, chemotactic protein. Here, we show that CX3CL1 overexpression is a positive prognostic marker in breast cancer. CX3CL1 overexpression attracted tumor-suppressive lymphocytes, including NK cells, and inhibited tumor growth and lung metastasis in the syngeneic 4T1 breast cancer mouse model. In HER2(+) SKBR3, MDA-MB-453, and HT-29 tumor cells, CX3CL1 overexpression increased NK cellmediated cytotoxicity in vitro and acted synergistically with trastuzumab. Even though CX3CL1 did not further improve trastuzumab efficacy in vivo in the trastuzumab-sensitive MDA-MB-453 model, it compensated for NK-cell depletion and prolonged survival. In the HER2 low-expressing HT-29 model, however, CX3CL1 overexpression not only prolonged survival time but also overcame trastuzumab resistance in a partly NK cell-dependent manner. Taken together, these findings identify CX3CL1 as a feasible pharmacologic target to enable trastuzumab therapy in HER2 low-expressing cancers and render it a potential predictive biomarker to determine therapy responders
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