11 research outputs found
Normalization of the Lymph Node T Cell Stromal Microenvironment in lpr/lpr Mice Is Associated with SU5416-Induced Reduction in Autoantibodies
The vascular-stromal elements of lymph nodes can play important roles in regulating the activities of the lymphocytes within. During model immune responses, the vascular-stromal compartment has been shown to undergo proliferative expansion and functional alterations. The state of the vascular-stromal compartment and the potential importance of this compartment in a spontaneous, chronic model of autoimmunity have not been well studied. Here, we characterize the vascular expansion in MRL-lpr/lpr lymph nodes and attempt to ask whether inhibiting this expansion can interfere with autoantibody generation. We show that characteristics of vascular expansion in enlarging MRL-lpr/lpr lymph nodes resemble that of the VEGF-dependent expansion that occurs in wild-type mice after model immunization. Surprisingly, treatment with SU5416, an inhibitor of VEGF and other receptor tyrosine kinases, did not have sustained effects in inhibiting vascular growth, but attenuated the anti-dsDNA response and altered the phenotype of the double negative T cells that are expanded in these mice. In examining for anatomic correlates of these immunologic changes, we found that the double negative T cells are localized within ectopic follicles around a central B cell patch and that these T cell-rich areas lack the T zone stromal protein ER-TR7 as well as other elements of a normal T zone microenvironment. SU5416 treatment disrupted these follicles and normalized the association between T zone microenvironmental elements and T cell-rich areas. Recent studies have shown a regulatory role for T zone stromal elements. Thus, our findings of the association of anti-dsDNA responses, double negative T cell phenotype, and altered lymphocyte microenvironment suggest the possibility that lymphocyte localization in ectopic follicles protects them from regulation by T zone stromal elements and functions to maintain autoimmune responses. Potentially, altering the lymphocyte microenvironment that is set up by the vascular-stromal compartment can be a means by which to control undesired autoimmune responses
The expression level of the transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) determines cellular survival after radiation treatment
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South African National Survey of Research & Experimental Development 2007/08
Commissioned by the Department of Science and Technology (DST)The National Survey of Research and Experimental Development (R&D) is conducted annually by the Human Sciences Research Council's Centre for Science, Technology and Innovation Indicators (CeSTII) on behalf of the Department of Science and Technology. R&D surveys provide data, collected under strict conditions of confidentiality that are essential for planning at
system and institutional level and provide snapshots of key indicators of national competitiveness. The R&D Surveys involve the collection of primary data from the public and private sectors. The public sector includes universities, science councils and government department-based research institutes, and the private sector includes firms and not-for-profit organisations. Between 2001 and 2006, there was a steady increase in South Africa's gross expenditure on R&D (GERD), which rose from 0.73% to 0.95% of GDP. However, the current survey points to a slight decrease in GERD to 0.93% of GDP. Over the same period, the South African economy performed favourably, attaining a GDP growth rate of around 5% and sustained employment growth from the beginning of 2005, which peaked in the third quarter of 2008. The R&D Survey results indicate that both the investment in R&D and the growth in the number of researchers lagged behind these important developments. These observations will be carefully
analysed to identify any emerging trends and to inform appropriate policy responses that may be needed, especially if we are to attain the target of GERD reaching 1% of GDP.
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South African National Survey of Research & Experimental Development, 2007/08
Commissioned by the Department of Science and Technology, NovemberAs part of the series of the National Survey of Research and Experimental Development (R&D Survey), the 2007/08 report has maintained the tradition both of substantively informing on national investment in scientific research activities and of providing the required data for monitoring levels of investment in R&D in South Africa. In particular, it provides the estimates of expenditure required for populating Indicator 10, expenditure on R&D as a percentage of GDP, in the Development Indicators 2009 publication by the Presidency. The report is also consistently aligned with the previous two R&D Survey reports (2006/07 and 2005/06), apart from minor adjustments to the sampling methodology in the not-for-profit sector. The minor adjustments involved the introduction of a short questionnaire, which was administered together with the usual long questionnaire, in order to collect the minimum information from those respondents that preferred a condensed version of the questionnaire to a long questionnaire. There are no noticeable contradictions either in the data provided or the trends between the results of the two questionnaires. The information coverage of the five sectors the business enterprise, government, higher education, not-for-profit and science council sectors is adequate.
The methodology is adequate for the purpose, pending further refinement of sampling in the not-for-profit sector with support from Statistics South Africa. Given the very small size of the not-for-profit sector, relatively negligible bias in the results can be expected