923 resultados para expansion of existing schools
Resumo:
We have used a PCR-based technology to study the V beta 5 and V beta 17 repertoire of T-cell populations in HLA-DR2 multiple sclerosis (MS) patients. We have found that the five MS DR2 patients studied present, at the moment of diagnosis and prior to any treatment, a marked expansion of a CD4+ T-cell population bearing V beta 5-J beta 1.4 beta chains. The sequences of the complementarity-determining region 3 of the expanded T cells are highly homologous. One shares structural features with that of the T cells infiltrating the central nervous system and of myelin basic protein-reactive T cells found in HLA-DR2 MS patients. An homologous sequence was not detectable in MS patients expressing DR alleles other than DR2. However, it is detectable but not expanded in healthy DR2 individuals. The possible mechanisms leading to its in vivo proliferation at the onset of MS are discussed.
Resumo:
We describe a novel approach to assay the ability of particular gene products to signal transitions in lymphocyte differentiation in vivo. The method involves transfection of test expression constructs into RAG-1-deficient embryonic stem cells, which are subsequently assayed by the RAG-2-deficient blastocyst complementation approach. We have used this method to demonstrate that expression of activated Ras in CD4-8- (double negative, DN) prothymocytes in vivo induces their differentiation into small CD4+8+ (double positive, DP) cortical thymocytes with accompanying expansion to normal thymocyte numbers. However, activated Ras expression in DP cells does not cause proliferation or maturation to CD4+8- or CD4-8+ (single positive) thymocytes. Therefore, signaling through Ras is sufficient for promoting differentiation of DN to DP cells, but further differentiation requires the activity of additional signaling pathways.
Resumo:
Huntington's disease (HD) is an inherited neurodegenerative disorder associated with expansion of a CAG repeat in the IT15 gene. The IT15 gene is translated to a protein product termed huntingtin that contains a polyglutamine (polyGln) tract. Recent investigations indicate that the cause of HD is expansion of the polyGln tract. However, the function of huntingtin and how the expanded polyGln tract causes HD is not known. We investigate potential protein-protein interactions of huntingtin using affinity resins. Huntingtin from brain extracts is retained on calmodulin(CAM)-Sepharose in a calcium-dependent fashion. We purify rat huntingtin to apparent homogeneity using a combination of DEAE-cellulose column chromatography, ammonium sulfate precipitation, and preparative SDS/PAGE. Purified rat huntingtin does not interact with CAM directly as revealed by 125I-CAM overlay. Huntingtin forms a large CAM-containing complex of over 1,000 kDa in the presence of calcium, which partially disassociates in the absence of calcium. Furthermore, an increased amount of mutant huntingtin from HD patient brains is retained on CAM-Sepharose compared to normal huntingtin from control patient brains, and the mutant allele is preferentially retained on CAM-Sepharose in the absence of calcium. These results suggest that huntingtin interacts with other proteins including CAM and that the expansion of polyGln alters this interaction.
Resumo:
The conventional approach to cytotoxic T-lymphocyte (CTL) induction uses maximal antigen concentration with the intent of eliciting more CTL. However, the efficacy of this approach has not been systematically explored with regard to the quality of the CTLs elicited or their in vivo functionality. Here, we show that a diametrically opposite approach elicits CTLs that are much more effective at clearing virus. CTLs specific for a defined peptide epitope were selectively expanded with various concentrations of peptide antigen. CTLs generated with exceedingly low-dose peptide lysed targets sensitized with > 100-fold less peptide than CTLs generated with high-dose peptide. Differences in expression of T-cell antigen receptors or a number of other accessory molecules did not account for the functional differences. Further, high-avidity CTLs adoptively transferred into severe combined immunodeficient mice were 100- to 1000-fold more effective at viral clearance than the low-avidity CTLs, despite the fact that all CTL lines lysed virus-infected targets in vitro. Thus, the quality of CTLs is as important as the quantity of CTLs for adoptive immunotherapy, and the ability to kill virally infected targets in vitro is not predictive of in vivo efficacy, whereas the determinant density requirement described here is predictive. Application of these principles may be critical in developing effective adoptive cellular immunotherapy for viral infections and cancer.
Resumo:
Preface -- Outline of study -- Resolution of appreciation -- Introduction and summary -- Proposed ordinance -- Recommendations -- Existing conditions in Chicago -- The social evil and the saloon -- The social evil and the police -- Sources of supply -- Child protection and education -- Rescue and reform -- The social evil and its medical aspects -- Appendices: Text of revised statutes of Illinois and ordinances of the City of Chicago ; Tables ; Exhibits.
Resumo:
Guidelines for a gender-fair use of the languages represented in the ITN LCG network were analyzed comparatively for specific criteria. All institutional or governmental guidelines aim at attenuating male-biased representations that are brought about by certain grammatical structures of the respective language. These guidelines primarily focus on the use of masculine forms as generics because they reduce the visibility of women in language. The comparison shows that guidelines for English, a language without grammatical gender, emphasize neutralization as a means of referring to both sexes. This differs from grammatical gender languages, such as German and Italian, in which feminine-masculine word-pairs are recommended in order to avoid the masculine bias. The guidelines all aim to promote the formulation of comprehensive and readable texts that are free of discrimination.
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