881 resultados para Fine, David J
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Introduction : The redox properties of fine/ultrafine particles as well as nanoparticles (NP) are suggested to be important to explain their biological activity and could constitute a novel and promising metric for hazard evaluation. The acellular in vitro dithiothreitol (DTT) assay allows measuring this property. Objectives : (1) to evaluate sampling requirements for fine/ultrafine particle allowing measurement of their oxidative potential (2) to apply the methodology to occupational situations where particle from combustion sources are generated. Material and method : Sampling parameters (type of filters and loaded amount) and storage duration affecting the DTT measurements were evaluated. Based on these results, a methodological approach was defined and applied in two occupational situations where diesel and other combustion particles are present (toll station in a tunnel and mechanical yard for bus reparation). Results : Teflon filters loaded with diesel particles were found more suitable for the DTT assay, due to their better chemical inertness compared to quartz filters: after storage durations larger than 150 hours, an increased reactivity toward DTT was observed only with quartz filters. Reactivity was linearly correlated to the loaded mass until about 1000 μg/filter. Different redox reactivities were determined in both working places, with the mechanical yard presenting a higher DTT consumption rate. Discussion and conclusions : These results demonstrate the feasibility of this method to determine the oxidative potential of fine/ultrafine particles in occupational situations. We propose to include this approach for hazard assessment of work places with exposure to manufactured and other NP.
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Immunotherapy of cancer is often performed with altered "analog" peptide Ags optimized for HLA class I binding, resulting in enhanced immunogenicity, but the induced T cell responses require further evaluation. Recently, we demonstrated fine specificity differences and enhanced recognition of naturally presented Ag by T cells after vaccination with natural Melan-A/MART-1 peptide, as compared with analog peptide. In this study, we compared the TCR primary structures of 1489 HLA-A*0201/Melan-A(26-35)-specific CD8 T cells derived from both cohorts of patients. Although a strong preference for TRAV12-2 segment usage was present in nearly all patients, usage of particular TRAJ gene segments and CDR3alpha composition differed slightly after vaccination with natural vs analog peptide. Moreover, TCR beta-chain repertoires were broader after natural than analog peptide vaccination. In all patients, we observed a marked conservation of the CDR3beta amino acid composition with recurrent sequences centered on a glycyl-leucyl/valyl/alanyl-glycyl motif. In contrast to viral-specific TCR repertoires, such "public" motifs were primarily expressed by nondominant T cell clonotypes, which contrasted with "private" CDR3beta signatures frequently found in T cell clonotypes that dominated repertoires of individual patients. Interestingly, no differences in functional avidity were observed between public and private T cell clonotypes. Collectively, our data indicate that T cell repertoires generated against natural or analog Melan-A peptide exhibited slightly distinct but otherwise overlapping and structurally conserved TCR features, suggesting that the differences in binding affinity/avidity of TCRs toward pMHC observed in the two cohorts of patients are caused by subtle structural TCR variations.
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"Vegeu el resum a l'inici del document del fitxer adjunt."
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La preservació digital de la que parla la nostra literatura professional està plena de mites que pensem que s'han d'anar tombant un darrera l'altre, en aquesta presentació us els mencionarem.
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The dissertation studies the texts mentioning or alluding to the dynastic promise to David in the books of Samuel; in the concluding further perspectives it also overviews the occurrences of the promise in the books of Kings; in the appendix, it comments on the "Law of the King" in Deut 17,14-20, the last verse of which may contain an allusion to the Davidic promise. The study engages with recent discussion on the history of the text of 2 Sam 7. In a detailed textual commentary, it treats with all the differences between the main textual witnesses of the chapter, and apart from the evaluation of the individual variants, it attempts to answer the question whether the differences are due exclusively to the process of transmission, or they are of literary character. Special attention is paid to the value of 1 Chr 17 for the reconstruction of the oldest text of 2 Sam 7; the author hopes that the conclusions of this part of the dissertation may prove to be of some importance for a more general study of the reception of Samuel in Chronicles. The subsequent literary analysis of 2 Sam 7 and the other passages referring to the dynastic promise to David leads to two alternative datings of Nathan's oracle and consequently two alternative redactional hypotheses trying to give account of the emergence of the examined passages. In the concluding perspectives, the function of the promise in Samuel is compared with the occurrences of the motif in Kings; this comparison leads to tentative conclusions concerning the development of the relation of the two books.
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A BALB/c cloned T cell line directed against beef apo cytochrome c was shown to exhibit the Lyt-1+2- cell surface phenotype. The fine specificity of antigen recognition exhibited by the T cell clone was assessed by using a variety of peptide preparations obtained from cytochrome c of different sources. The peptide segment recognized by this T cell clone, in conjunction with I-A region gene products, appeared similar to that bound by a monoclonal antibody specific for beef apo cytochrome c derived from the same strain of mice.