A survey of the experience background of first grade children for the silver burdet readers

Thesis (Ed.M.)--Boston Universit

The Goldfish as a Model for Studying Neuroestrogen Synthesis, Localization, and Action in the Brain and Visual System

Organizational and activational effects of estrogen (E) in the central nervous system (CNS) are exerted directly by circulating E and indirectly after aromatization of circulating androgen to E in the brain itself. Understanding an environmental chemical's ability to disrupt E-dependent neural processes, therefore, requires attention to both pathways. Because aromatase (Aro) is highly expressed in teleost brain, when compared to mammals and other vertebrates, fish are technically advantageous for localization and regulation studies and may also provide a model in which the functional consequences of brain-derived (neuro-)E synthesis are exaggerated. Recently, Aro was immunolocalized in cell bodies and fiber projections of second- and third-order neurons of the goldfish retina and in central visual processing areas. Authentic Aro enzyme activity was verified biochemically, suggesting a heretofore unrecognized role of sex steroids in the visual system. Initial studies show that in vivo treatment with aromatizable androgen or E increases calmodulin synthesis and calmodulin protein in retina and also affects retinal protein and DNA. Whether there are related changes in the processing of visual information that is essential for seasonal reproduction or in the generative and regenerative capacity of the goldfish visual system requires further investigation. IMAGES.National Science Foundation (DCB8916809

CD40 is constitutively expressed on platelets and provides a novel mechanism for platelet activation

CD40 is a 48-kDa phosphorylated transmembrane glycoprotein belonging to the TNF receptor superfamily. CD40 has been demonstrated on a range of cell types, and it has an important role in adaptive immunity and inflammation. CD40 has recently been described on platelets but platelet activation by CD40 has not been described. In the present study, we use flow cytometry and immunoblotting to confirm that platelets constitutively express surface CD40. CD40 mRNA was undetectable, suggesting that the protein is synthesized early in platelet differentiation by megakaryocytes. Ligation of platelet CD40 with recombinant soluble CD40L trimer (sCD40LT) caused increased platelet CD62P expression, -granule and dense granule release, and the classical morphological changes associated with platelet activation. CD40 ligation also caused ß3 integrin activation, although this was not accompanied by platelet aggregation. These actions were abrogated by the CD40L blocking antibody TRAP-1 and the CD40 blocking antibodies M2 and M3, showing that activation was mediated by CD40L binding to platelet CD40. ß3 integrin blockade with eptifibatide had no effect, indicating that outside-in signaling via IIbß3 was not contributing to these CD40-mediated effects. CD40 ligation led to enhanced platelet-leukocyte adhesion, which is important in the recruitment of leukocytes to sites of thrombosis or inflammation. Our results support a role for CD40-mediated platelet activation in thrombosis, inflammation, and atherosclerosis

Heterogeneity in thymic emigrants: implications for thymectomy and immunosenescence.

The development of mature, antigen-inexperienced (naive) T cells begins in the thymus and continues after export into the periphery. Post-thymic maturation of naive T cells, in humans, coincides with the progressive loss of markers such as protein tyrosine kinase 7 (PTK7) and platelet endothelial cell adhesion molecule-1 (CD31). As a consequence, subpopulations of naive T cells can be recognised raising questions about the processes that give rise to the loss of these markers and their exact relationship to recent thymic emigrants (RTE). Here, we combine a mathematical survival analysis approach and data from healthy and thymectomised humans to understand the apparent persistence of populations of 'veteran' PTK7 (+) T cells in thymectomised individuals. We show that a model of heterogeneity in rates of maturation, possibly linked to natural variation in TCR signalling thresholds or affinity for self-antigens, can explain the data. This model of maturation predicts that the average post-thymic age of PTK7 (+) T cells will increase linearly with the age of the host suggesting that, despite the immature phenotype, PTK7 (+) cells do not necessarily represent a population of RTE. Further, the model predicts an accelerated increase in the average post-thymic age of residual PTK7 (+) T cells following thymectomy and may also explain in part the prematurely aged phenotype of the naive T cell pool in individuals thymectomised early in life

Plasmonic-photonic crystal coupled nanolaser

We propose and demonstrate a hybrid photonic-plasmonic nanolaser that combines the light harvesting features of a dielectric photonic crystal cavity with the extraordinary confining properties of an optical nano-antenna. In that purpose, we developed a novel fabrication method based on multi-step electron-beam lithography. We show that it enables the robust and reproducible production of hybrid structures, using fully top down approach to accurately position the antenna. Coherent coupling of the photonic and plasmonic modes is highlighted and opens up a broad range of new hybrid nanophotonic devices

Tobacco Control and the World Trade Organization : Mapping Member States’ Positions after the Framework Convention on Tobacco Control

Objective To note the frequency of discussions and disputes about tobacco control measures at the World Trade Organization (WTO) before and after the coming into force of the Framework Convention on Tobacco Control (FCTC). To review trends or patterns in the positions taken by members of the WTO with respect to tobacco control measures. To discuss possible explanations for these observed trends/patterns. Methods We gathered data on tobacco-related disputes in the WTO since its establishment in 1995 and its forerunner, the General Agreement on Tariffs and Trade (GATT), prior-FCTC and post-FCTC. We also looked at debates on tobacco control measures within the WTO more broadly. To this end, we classified and coded the positions of WTO member states during discussions on tobacco control and the FCTC, from 1995 until 2013, within the Technical Barriers to Trade (TBT) Committee and the Trade-Related Aspects of Intellectual Property Rights (TRIPS) Council. Results There is a growing interest within the WTO for tobacco-related issues and opposition to tobacco control measures is moving away from high-income countries towards low(er) income countries. Conclusions The growing prominence of tobacco issues in the WTO can be attributed at least in part to the fact that during the past decade tobacco firms have been marginalised from the domestic policy-making process in many countries, which has forced them to look for other ways and forums to influence decision-making. Furthermore, the finding that almost all recent opposition within the WTO to stronger tobacco regulations came from developing countries is consistent with a relative shift of transnational tobacco companies’ lobbying efforts from developed to developing countries

Epicutaneous Immunization with Type II Collagen Inhibits both Onset and Progression of Chronic Collagen-Induced Arthritis

Epicutaneous immunization is a potential non-invasive technique for antigen-specific immune-modulation. Topical application of protein antigens to barrier-disrupted skin induces potent antigen-specific immunity with a strong Th2-bias. In this study, we investigate whether the autoimmune inflammatory response of chronic collagen-induced arthritis (CCIA) in DBA/1-TCR-beta Tg mice can be modified by epicutaneous immunization. We show that epicutaneous immunization with type II collagen (CII) inhibited development and progression of CCIA and, importantly, also ameliorated ongoing disease as indicated by clinical scores of disease severity, paw swelling and joints histology. Treated mice show reduced CII-driven T cell proliferation and IFN-gamma production, as well as significantly lower levels of CII-specific IgG2a serum antibodies. In contrast, CII-driven IL-4 production and IgE antibody levels were increased consistent with skewing of the CII response from Th1 to Th2 in treated mice. IL-4 production in treated mice was inversely correlated with disease severity. Moreover, T cells from treated mice inhibited proliferation and IFN-gamma production by T cells from CCIA mice, suggesting induction of regulatory T cells that actively inhibit effector responses in arthritic mice. The levels of CD4(+)CD25(+) T cells were however not increased following epicutaneous CII treatment. Together, these results suggest that epicutaneous immunization may be used as an immune-modulating procedure to actively re-programme pathogenic Th1 responses, and could have potential as a novel specific and simple treatment for chronic autoimmune inflammatory diseases such as rheumatoid arthritis