Thiol-containing compounds such as glutathione, cysteine and homocysteine react with selenite under specific conditions to form selenotrisulfides of significance in cellular systems. This study describes the synthesis and mass spectrometric characterization of selenotrisulfides of glutathione (GSH), cysteine (Cys) and homocysteine (HCys) by electrospray-MS (ESI-MS). The synthesized species are separated by reversed phase-ion pairing HPLC and detected by selective monitoring of Se (m/z 77, 78 and 80) using a collision/reaction cell-inductively coupled plasma-mass spectrometer (CRC-ICP-MS). The cell is pressurized using H 2 as reaction gas at a flow of 3.5 ml min 21 for minimizing Ar polyatomic ions affecting m/z 78 and 80. Separation of the species is performed in a C 8 column with a mobile phase containing 12% methanol and 0.05% heptafluorobutyric acid (HFBA). Using this hyphenated system (HPLC-ICP-MS) LDs below 1 ppb were attained for all the species under study. HPLC-ICP-MS was used also as a tool to study the presence of an excess of GSH and the pH influence on the stability of the Se-glutathion conjugate (GS-Se-SG) as model. Similarly, GS-Se-SG is evaluated as a possible substrate for the enzyme glutathione reductase (GR) in the presence of NADPH. The isolation and HPLC-ICP-MS detection of the synthesized selenotrisulfides in rat liver cytosols of exposed animals will be also discussed.

The MLL gene, at 11q23, undergoes chromosomal translocation with a large number of partner genes in both acute lymphoblastic and acute myeloid leukemia (AML). We report a novel t(9;11;19)(p22;q23;p13.3) disrupting MLL in an infant AML patient. The 5' end of MLL fused to chromosome 9 sequences on the der(11), whereas the 3' end was translocated to chromosome 19. We developed long-distance inverse-polymerase chain reaction assays to investigate the localization of the breakpoints on der(11) and der(19). We found that intron 5 of MLL was fused to intron 5 of MLLT3 at the der(11) genomic breakpoint, resulting in a novel in-frame MLL exon 5-MLLT3 exon 6 fusion transcript. On the der(19), a novel gene annotated as FLJ10374 was disrupted by the breakpoint. Using reverse transcription-polymerase chain reaction analysis, we showed that FLJ10374 is ubiquitously expressed in human cells. Transfection of the FLJ10374 protein in different cell lines revealed that it localized exclusively to the nucleus. In serum-starved NIH-3T3 cells, the expression of FLJ10374 decreased the rate of the G1-to-S transition of the cell cycle, whereas the suppression of FLJ10374 through short interfering RNA increased cell proliferation. These results indicate that FLJ10374 negatively regulates cell cycle progression and proliferation. Thus, a single chromosomal rearrangement resulting in formation of the MLL-MLLT3 fusion gene and haplo-insufficiency of FLJ10374 may have cooperated to promote leukemogenesis in AML with t(9;11;19).

The results of this study demonstrating clinically relevant sex-related differences in the pathophysiology of the hyperthyroid heart have raised new questions regarding the mechanisms responsible for the observed differences. This study suggests that sex-related intrinsic factors such as nitric oxide may modulate the response to hyperthyroidism that leads to cardiovascular dysfunction.

2007 1 RESUMOAs estratégias construtivistas na obra de Hélio Oiticica estão compreendidas na noção definida pelo artista de "mundo erigindo mundo". Esta estratégia é identificável tanto nos aspectos éticos e estéticos das proposições de Oiticica quanto na maneira como seu próprio pensamento é construído de blocos achados nas obras de filósofos, músicos e outros artistas.Este trabalho percorre manuscritos de Hélio Oiticica disponíveis em arquivos digitais para identificar os blocos de pensamento que embasam a produção de Hélio Oiticica, identificando a singularidade de sua obra frente a propostas de alguns de seus contemporâneos.Ainda que reconhecendo a importância do mito e da Mangueira na obra do inventor da Tropicália, o texto enfatiza que a "síntese" feita por Hélio Oiticica não se deixa fixar em um estereótipo cultural já que escapa dos espaços delimitados e do tempo cronológico, estabelecendo-se em um "mundo-abrigo" virtual, onde Oiticica acha fragmentos das produções de inventores de vários lugares e épocas para compor seu programa além-da-arte. Palavras-chaves:Construtivismo; Experimental; Nietzsche; Eterno Retorno; Arte Brasileira. 2 ABSTRACTThe constructivist strategies within Hélio Oiticica´s oeuvre are comprehended in the notion of "world building world" articulated by the artist. This strategy is discernible both on the ethic and aesthetic aspects of Oiticica´s proposals and on the way his own thought is built out of blocks he found in works by philosophers, musicians and other artists.This text traverses manuscripts by Hélio Oiticica, available in digital archives, to identify the building blocks of the artist´s thought and its singularity in relation to proposals of some of his contemporaries.Although recognizing the importance of the myth and of the Mangueira samba school on the work of the inventor of Tropicalia, this text emphasizes that the "synthesis" produced by Hélio Oiticica defies cultural stereotypes since it escapes boundaries and the chronological time, establishing itself within a "world-shelter" where the artist finds fragments of the production of other inventors from different cultures and times, to compose his own beyond-the-art program.Keywords: Constructivism; Experimental; Nietzsche; Eternal Return; Brazilian Art. 3Para Roberto Braga, que adorava as escolas de samba. AGRADECIMENTOSA orientação que recebi de Celso Favaretto foi imprescindível para a escrita desse texto. Além de precioso impulso acadêmico, contei com seu apoio em períodos difíceis e palavras certas nas horas certas. Sou profundamente grata a meu orientador.Minha pesquisa foi imensamente facilitada pelos arquivos digitalizados de manuscritos de Hélio Oiticica. Agradeço às pessoas e instituições envolvidas na especificação e manutenção do Programa HO e Arquivo HO e em especial ao Projeto HO por me ceder o arquivo digital e fotografias que uso nesse trabalho.Durante mais de um ano, tive também em mãos o arquivo pessoal de documentos e anotações de Beatriz Scigliano Carneiro sobre Hélio Oiticica, que além desse emprés...