Do ciberespaço à iconomia: projeções metapóricas

Na sociedade contemporânea o ser humano se vê inserido – ou invadido – em ambientes cada vez mais configurados por complexos recursos tecnológicos. É o ciberespaço, onde as imagens inundam o cotidiano e se traduzem em valor, o corpo adquire novo status imaterial e as noções de lugar e tempo se transformam e quase se anulam. O cinema pensa e produz também uma desterritorialização da imagem em movimento desde os seus primeiros tempos de imagem-máquina. Este trabalho reflete sobre as transformações da ordem social que implicam a emergência de uma “iconomia” a partir dos espaços simbólicos, tomando três momentos críticos na história do cinema como índices de uma convergência entre material e imaterial que se consolida a partir da emergência do ciberespaço. O quase-método metapórico é mobilizado como ferramenta de reconstrução metodológica desses ícones da história do cinema relacionados à desconstrução do Homo faber. O “outro lado” do ciberespaço, abrindo continuamente novos espaços-tempos de criação de valor, identifica-se a uma iconomia em que as projeções narrativas tornam-se fontes paradigmáticas de valor e de “mais gozar”.

Base-Paired and Base-Stacked Structures of the Anti-HIV Drug Lamivudine: A Nucleoside DNA-Mimicry with Unprecedented Topology

We have prepared a DNA-mimicry of nucleosides in which the anti-HIV drug lamivudine (beta-L-2',3'-dideoxy-3'-thiacytidine, 3TC) self-assembles into a base-paired and helically base-stacked hexagonal structure. Face-to-face and face-to-tail stacked 3TC=3TC dimers base-paired through two hydrogen bonds between neutral cytosines by either N-H center dot center dot center dot O or N-H center dot center dot center dot N atoms give rise to a right-handed DNA-mimicry of lamivudine with an unusual highly symmetric hexagonal lattice and topology. In addition, a base-paired and base-stacked supramolecular architecture of lamivudine hemihydrochloride hemihydrate was also obtained as a result of our crystal screenings. This structure is formed through partially face-to-face stacked lamivudine pairs held together by protonated and neutral fragments. However, no helical stacking occurs in this structure in which lamivudine also adopts unusual conformations as the C1'-endo and C1'-exo sugar puckers and cytosine orientations intermediate between the anti and syn conformations. As a conclusion drawn from the nucleoside duplex, the hexagonal DNA-mimicry of lamivudine reveals that such double-stranded helices can be assembled without counterions and organic solvents but with higher crystallographic symmetry instead, because only water crystallizes together with lamivudine in this structure.

Wilson's disease: an analysis of 28 Brazilian children

OBJECTIVES: Clinical-laboratory and evolutionary analysis of twenty-eight patients with Wilson's disease. METHODS: Twenty-eight children (twelve females and sixteen males) with Wilson's disease were evaluated retrospectively between 1987 and 2009, with a follow-up of 72 months (1 -240 months). The clinical, laboratory, and histologic features at diagnosis were recorded at the end of the study. RESULTS: The median age at diagnosis was 11 years (2 -18 years). Twelve patients were asymptomatic, seven had hepatitis symptoms, five had raised aminotransferase levels, three had hepatomegaly associated with neurological disorders, one had fulminant hepatitis with hemolytic anemia, and six patients presented with a Kayser-Fleischer ring. A histological analysis revealed that six children had chronic hepatitis, seven had cirrhosis, two had steatosis, one had portal fibrosis, and one had massive necrosis. The treatment consisted of D-penicillamine associated with pyridoxine for 26 patients. Adverse effects were observed in the other two patients: one presented with uncontrollable vomiting and the other demonstrated elastosis perforans serpiginosa. At the end of the study, all 26 treated patients were asymptomatic. Twenty-four of the patients were treated with D-penicillamine and pyridoxine, and two were treated with trientine and zinc sulfate. A liver transplant was performed in one patient with fulminant hepatitis, but the final patient died 48 hours after admission to the intensive care unit. CONCLUSIONS: Family screenings associated with early treatment are important in preventing Wilson's disease symptoms and potentially fatal disease progression. The study suggests that Wilson's disease must be ruled out in children older than two years presenting with abnormal levels of hepatic enzymes because of the heterogeneity of symptoms and the encouraging treatment results obtained so far.