979 research outputs found

    The convergence of radiation and immunogenic cell death signaling pathways.

    Get PDF
    Ionizing radiation (IR) triggers programmed cell death in tumor cells through a variety of highly regulated processes. Radiation-induced tumor cell death has been studied extensively in vitro and is widely attributed to multiple distinct mechanisms, including apoptosis, necrosis, mitotic catastrophe (MC), autophagy, and senescence, which may occur concurrently. When considering tumor cell death in the context of an organism, an emerging body of evidence suggests there is a reciprocal relationship in which radiation stimulates the immune system, which in turn contributes to tumor cell kill. As a result, traditional measurements of radiation-induced tumor cell death, in vitro, fail to represent the extent of clinically observed responses, including reductions in loco-regional failure rates and improvements in metastases free and overall survival. Hence, understanding the immunological responses to the type of radiation-induced cell death is critical. In this review, the mechanisms of radiation-induced tumor cell death are described, with particular focus on immunogenic cell death (ICD). Strategies combining radiotherapy with specific chemotherapies or immunotherapies capable of inducing a repertoire of cancer specific immunogens might potentiate tumor control not only by enhancing cell kill but also through the induction of a successful anti-tumor vaccination that improves patient survival

    Eco-innovative food in Brazil: perceptions from producers and consumers

    Get PDF
    The main focus of this paper is to analyse the production and consumption for eco-innovative food in Brazil. The research can be divided in two parts: the first, focusing in the supply-side, aims to identify food companies’ motivation to adopt eco-innovation, and the second, in the demand-side, to investigate consumer values and attitudes towards eco-innovation. In order to analyse the supply-side, an exploratory phase has been conducted with 13 in-depth interviews with firms and organizations that work with eco-innovative food, green certifications and green food associations. The analysis of the demand-side was carried out through an exploratory phase, with 42 interviews in green and organic fairs and street markets along with a Survey with 401 consumers in traditional Organic Street Markets in Porto Alegre, Brazil. The quantitative data from this stage was analysed with SPSS (univariate statistics). Results indicate that the companies’ mission and strategy are important drivers for the adoption of eco-innovations in the food sector. Technology is an essential input for the supply side, and can act as an important driver to increase the supply of sustainable food, to reduce losses, and to improve environmental sustainability. The eco-innovative market has a great potential to grow and become more competitive, although some barriers still need to be transposed: clearer regulations, logistics, high quality manpower and production of more convenient products for consumers. Results from the analysis of consumers indicate the presence of egalitarian values, and positive attitudes towards environment and technological progress, as well as a positive attitude and intention to buy eco-innovative food. Additional findings points out towards a certain belief on behalf of Brazilian consumers that technology can be a determinant of relevant aspects of eco-innovative foods. This research is of particular academic value, by adding empirical evidence about the relationships that rule how values and general attitudes influence attitudes towards eco-innovative food in the Brazilian food consumption context. Managerial implications are related to the need for companies to remain competitive and profitable, and innovation and environmental sustainability can be used as an alternative to mitigate environmental risks derived from the company’s activities

    Área do piquete e taxa de lotação no pastejo rotacionado.

    Get PDF
    ABSTRACT: During the last two decades, rotational grazing has been increasingly adopted in cattle farms in the Cerrado Region. However, many farmers and extensionists are still having problems in designing efficient pastoral systems based on rotational grazing. This paper briefly describes the basic concepts of this grazing method and provides key steps to be followed in planning pasture area and stocking rate in rotational grazing.bitstream/CPAC-2009/27320/1/comtec_101.pd

    The state of peer-to-peer network simulators

    Get PDF
    Networking research often relies on simulation in order to test and evaluate new ideas. An important requirement of this process is that results must be reproducible so that other researchers can replicate, validate and extend existing work. We look at the landscape of simulators for research in peer-to-peer (P2P) networks by conducting a survey of a combined total of over 280 papers from before and after 2007 (the year of the last survey in this area), and comment on the large quantity of research using bespoke, closed-source simulators. We propose a set of criteria that P2P simulators should meet, and poll the P2P research community for their agreement. We aim to drive the community towards performing their experiments on simulators that allow for others to validate their results

    PTPRC (CD45) is not associated with multiple sclerosis in a large cohort of German patients

    Get PDF
    BACKGROUND: Since contradictory results have been reported, we reanalysed the 77C→G transition in exon 4 of the protein-tyrosine phosphatase receptor-type C (PTPRC also known as CD45) in a large cohort of German MS patients and controls. Different isoforms of the protein are expressed, depending on alternative splicing of exons 4 (CD45RA), 5 (CD45RB) and 6 (CD45RC) (CD45RO, exons 4–6 spliced out). The 77C→G transition does not change the amino acid sequence, but it is probably part of a motif necessary for splicing leading to the isoform CD45RA. The expression of CD45RA is increased in 77C/G heterozygous individuals. The aim of the study was to clarify the importance of the PTPRC 77C→G transition in our German cohort of MS patients. METHODS: PCR products of exon 4 were digested using endonuclease MspI. The resulting restriction fragments of the wildtype C allele are 198 and 62 bp in length. In the G allele an additional restriction site is present yielding fragments of 114 and 84 bp. RESULTS: The G allele was identified in 10 of the 347 controls (1.4%) and in 7 of 454 MS patients (0.8%; Table 1). No homozygous individuals were found either in the control or in the patient group. Genetic association between the PTPRC 77C→G transition and MS susceptibility was excluded in the MS cohort. In addition, subgrouping patients according to differences in the clinical course of MS or according to HLA-DRB1*15 status did not yield significant differences. CONCLUSIONS: The 77C→G transition in exon 4 of the PTPRC gene may contribute to MS susceptibility only in very few families, if at all, but it is not relevant for the majority of MS cases, including virtually all German patients

    MS Sunshine Study: Sun Exposure But Not Vitamin D Is Associated with Multiple Sclerosis Risk in Blacks and Hispanics

    Get PDF
    Multiple sclerosis (MS) incidence and serum 25-hydroxyvitamin D (25OHD) levels vary by race/ethnicity. We examined the consistency of beneficial effects of 25OHD and/or sun exposure for MS risk across multiple racial/ethnic groups. We recruited incident MS cases and controls (blacks 116 cases/131 controls; Hispanics 183/197; whites 247/267) from the membership of Kaiser Permanente Southern California into the MS Sunshine Study to simultaneously examine sun exposure and 25OHD, accounting for genetic ancestry and other factors. Higher lifetime ultraviolet radiation exposure (a rigorous measure of sun exposure) was associated with a lower risk of MS independent of serum 25OHD levels in blacks (adjusted OR = 0.53, 95% CI = 0.31-0.83; p = 0.007) and whites (OR = 0.68, 95% CI = 0.48-0.94; p = 0.020) with a similar magnitude of effect that did not reach statistical significance in Hispanics (OR = 0.66, 95% CI = 0.42-1.04; p = 0.071). Higher serum 25OHD levels were associated with a lower risk of MS only in whites. No association was found in Hispanics or blacks regardless of how 25OHD was modeled. Lifetime sun exposure appears to reduce the risk of MS regardless of race/ethnicity. In contrast, serum 25OHD levels are not associated with MS risk in blacks or Hispanics. Our findings challenge the biological plausibility of vitamin D deficiency as causal for MS and call into question the targeting of specific serum 25OHD levels to achieve health benefits, particularly in blacks and Hispanics

    Vitamin D-Binding Protein Polymorphisms, 25-Hydroxyvitamin D, Sunshine and Multiple Sclerosis

    Get PDF
    Blacks have different dominant polymorphisms in the vitamin D-binding protein (DBP) gene that result in higher bioavailable vitamin D than whites. This study tested whether the lack of association between 25-hydroxyvitamin D (25OHD) and multiple sclerosis (MS) risk in blacks and Hispanics is due to differences in these common polymorphisms (rs7041, rs4588). We recruited incident MS cases and controls (blacks 116 cases/131 controls; Hispanics 183/197; whites 247/267) from Kaiser Permanente Southern California. AA is the dominant rs7041 genotype in blacks (70.0%) whereas C is the dominant allele in whites (79.0% AC/CC) and Hispanics (77.1%). Higher 25OHD levels were associated with a lower risk of MS in whites who carried at least one copy of the C allele but not AA carriers. No association was found in Hispanics or blacks regardless of genotype. Higher ultraviolet radiation exposure was associated with a lower risk of MS in blacks (OR = 0.06), Hispanics and whites who carried at least one copy of the C allele but not in others. Racial/ethnic variations in bioavailable vitamin D do not explain the lack of association between 25OHD and MS in blacks and Hispanics. These findings further challenge the biological plausibility of vitamin D deficiency as causal for MS
    corecore