74 research outputs found

    Compilation of results of the ICPPR non-Apis working group with a special focus on the bumblebee acute oral and contact toxicity ring test 2014 ICPPR Non-Apis Working Group

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    Although honeybee risk assessment for chemicals has been rigorously revised recently, methods and techniques available for non-apis pollinators are scarce. An ICPPR working group “non-apis” was established in 2013 to address these knowledge gaps. Acute contact tests were designed and performed with solitary bees Osmia sp. but still require further optimization. Ring tests on acute oral and contact toxicity for the bumblebee Bombus sp. were developed and performed in 2014. Thirteen European laboratories participated in the trials and in most cases control mortality was < 10% after 96h, indicating that the developed methodologies were feasible in a variety of laboratories. The oral exposure and the group contact exposure tests were each found to generate more variable LD50 estimates, whereas the endpoints obtained in the single contact tests were more consistent among laboratories. The difference in the two different contact test designs indicates the presence of a ‘housing’ effect, which makes the group housing less favorable. In addition, the use of Tween80 as a wetting agent was found to be unsuccessful

    Transcriptional activity of the 5′-flanking region of the thyroid transcription factor-1 gene in human thyroid cell lines

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    Thyroid transcription factor-1 (TTF-1, NKX2-1) is a homeodomain-containing transcriptional factor that binds to and activates the promoters of thyroid and lung-specific genes, such as thyroglobulin, thyroid peroxidase, and thyroid stimulating hormone receptor. TTF-1 is known to play a key role in the development of the thyroid. However, the precise mechanism of TTF-1 gene transcription in human thyroid cells has not been studied. The expression of transcriptional activity in various lengths of the 5′-flanking region of the human TTF -1 gene was studied in TTF-1 positive and negative human thyroid cell lines. Increased transcriptional activity was observed in thyroid cell lines containing plasmids that coded for a sequence proximal to the transcription start site of exon 1 of the TTF-1 gene. However, we did not observe any difference in promoter activity in the region up to −2.6 kb from the proximal transcription start site of the TTF-1 gene between TTF-1 positive and negative cells. These results suggest that the proximal 5′-flanking region of the human TTF -1 gene does not contain sufficient cis-active regulatory information to direct gene expression in thyroid cells, and that other cis- or trans-acting factors participate in the thyroid specific gene expression of TTF-1

    PNEUMOMETRY

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    Reanimation cardio-pulmonaire en Suisse: le temps d'agir! [Cardiopulmonary resuscitation in Switzerland: time to act!]

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    Cardiovascular related deaths still represent about 50% of all demises despite their decreasing incidence in the United States and in Switzerland. About two thirds of these deaths are due to ischemic heart disease in which half of the patients die outside hospital, the majority of them two hours after the first symptoms. Moreover, sudden death is the first symptom of coronary artery disease in 25% of cases. In this country few of these persons receive adequate basic life support (BLS) at the scene because a coordinated plan to teach BLS to the citizen does not yet exist in Switzerland. With the aid of specialized medical societies, the Swiss Red Cross and affiliated organizations, it is proposed to elaborate a plan to teach BLS to the general public in Switzerland on the basis of the future European guidelines for BLS

    Stabilized beta-catenin in thymic epithelial cells blocks thymus development and function.

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    Thymic T cell development is dependent on a specialized epithelial microenvironment mainly composed of cortical and medullary thymic epithelial cells (TECs). The molecular programs governing the differentiation and maintenance of TECs remain largely unknown. Wnt signaling is central to the development and maintenance of several organ systems but a specific role of this pathway for thymus organogenesis has not yet been ascertained. In this report, we demonstrate that activation of the canonical Wnt signaling pathway by a stabilizing mutation of beta-catenin targeted exclusively to TECs changes the initial commitment of endodermal epithelia to a thymic cell fate. Consequently, the formation of a correctly composed and organized thymic microenvironment is prevented, thymic immigration of hematopoietic precursors is restricted, and intrathymic T cell differentiation is arrested at a very early developmental stage causing severe immunodeficiency. These results suggest that a precise regulation of canonical Wnt signaling in thymic epithelia is essential for normal thymus development and function

    Forced expression of the non-coding RNA miR-17∼92 restores activation and function in CD28-deficient CD4+ T cells.

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    Funder: Horizon 2020 Framework ProgrammeFunder: National Institutes of HealthCD28 provides the prototypical costimulatory signal required for productive T-cell activation. Known molecular consequences of CD28 costimulation are mostly based on studies of protein signaling molecules. The microRNA cluster miR-17∼92 is induced by T cell receptor stimulation and further enhanced by combined CD28 costimulation. We demonstrate that transgenic miR-17∼92 cell-intrinsically largely overcomes defects caused by CD28 deficiency. Combining genetics, transcriptomics, bioinformatics, and biochemical miRNA:mRNA interaction maps we empirically validate miR-17∼92 target genes that include several negative regulators of T cell activation. CD28-deficient T cells exhibit derepressed miR-17∼92 target genes during activation. CRISPR/Cas9-mediated ablation of the miR-17∼92 targets Pten and Nrbp1 in naive CD28-/- CD4+ T cells differentially increases proliferation and expression of the activation markers CD25 and CD44, respectively. Thus, we propose that miR-17∼92 constitutes a central mediator for T cell activation, integrating signals by the TCR and CD28 costimulation by dampening multiple brakes that prevent T cell activation
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