Miopericardite tuberculosa associado a QT longo e torsades de pointes: relato de caso / Tuberculous myopericarditis associated with long QT and torsades de pointes: case report

INTRODUÇÃO: A tuberculose cardíaca é uma doença rara Estima-se que 1% de todos os casos de tuberculose têm envolvimento cardíaco produzido por disseminação linfática, contígua do pericárdio ou por via hematogênica. Miocardite tuberculosa pode permanecer clinicamente assintomática (com diagnóstico feito em autópsia), ou pode se apresentar com morte, arritmias ventriculares intratáveis, síndrome do QT longo, bloqueio cardíaco ou insuficiência cardíaca. Complicações cardíacas, como taquiarritmias ventriculares, são ainda mais raras, mas são potencialmente tratáveis se reconhecimento imediato. RELATO DE CASO: S.A.F.R., 55 anos, sexo feminino, com dispneia e palpitações há cerca de três meses da admissão no pronto socorro. ECG evidenciando QT longo (figura 1) Ecocardiograma mostrou derrame pericárdico com repercussão hemodinâmica. Realizada drenagem de Marfan de urgência. No 2 dia de pós-operatório, apresentou Taquicardia Ventricular (TV) Sustentada Monomórfica Instável. Após cardioversão elétrica, evoluiu com múltiplos episódios de TV com Torsades de Pointes. A arritmia ventricular foi atribuída a QT longo congênito. Medicada com lidocaína EV, passado fio de marcapasso provisório com persistência da arritmia. Análise do líquido pericárdico evidenciou adenosina deaminase de 110 U/l e ressonância magnética (figura 2) apresentando edema miocárdico e sinais de processo inflamatório. Feito diagnóstico de Miopericardite tuberculósica e iniciado esquema RIPE. Após 15 dias, observou-se normalização do intervalo QT e desaparecimento dos sintomas e das arritmias ventriculares, sem recidiva de derrame pericárdico. Evoluiu na sequência com quadro séptico, por endocardite infecciosa, trombo em fio de marcapasso e insuficiência tricúspide. Foi submetida a cirurgia para retirada de fio de marca-passo provisório e troca valvar tricúspide de urgência, evoluindo a óbito no pós-operatório. CONCLUSÃO: O QT longo, inicialmente pensado como congênito, foi considerado a causa das arritmias. O papel da inflamação na gênese do QT longo tem sido descrito e foi comprovado neste caso, pela normalização do intervalo e desaparecimento das arritmias com o tratamento específico da tuberculose. Alto grau de suspeição é importante para diagnóstico precoce, já que alguns casos de miocardite tuberculosa foram relatados no último anos na literatura inglesa, francesa e espanhola, todos eles diagnosticados na necropsia. A terapia antituberculose pode resultar em sucesso com regressão da doença e resolução de arritmias malignas. (AU)

In vitro antimicrobial activity of extracts and isolated constituents of Geum rivale.

The antimicrobial activity of extracts of Geum rivale (Rosaceae) and that of some isolated constituents, on bacteria and fungi, was evaluated. The activity was concentrated in the triterpenes fraction and, for gram+ and gram- bacteria, also in the flavonoids fraction.

Characterization of carrot nuclear proteins that exhibit specific binding affinity towards conventional and non-conventional DNA methylation.

DNA methylation is associated with transcriptional silencing in vertebrates and plants. In mammals, the effects of methylation are mediated by a family of methyl-CpG-binding proteins. In plants the mechanisms by which methylation represses transcription are still not clear. In this paper we describe protein factors in carrot nuclear extracts exhibiting specific affinities for conventional or non-conventional methylation acceptor sites. We characterized two classes of proteins: the first, dcMBPI (Daucus carota methylated DNA-binding protein 1), shows high affinity for sequences containing 5-methylcytosine; the second, dcMBP2 (Daucus carota methylated DNA-binding protein 2), efficiently complexes sequences containing 5-methylcytosine in both CpXpX and CpXpG trinucleotides and shows much lower affinity for 5-methyl CpG dinucleotides. Both dcMBP1 and dcMBP2 are abundant proteins differing in molecular weight and binding features. Their activities are modulated during carrot vegetative cell growth and somatic embryo development. This is the first time that, in either plants or mammals, proteins exhibiting specific binding affinities for conventional or non-conventional DNA methylation have been shown. Based on these results, the possibility that both the extent and the context of the methylation might contribute to modulate gene expression is discussed.

Cryptochrome 1 controls tomato development in response to blue light.

Cryptochrome genes (CRY) are a novel class of plant genes encoding proteins that bear a strong resemblance to photolyases, a rare class of flavoproteins that absorb light in the blue (B) and UV-A regions of the spectrum and utilise it for photorepair of UV-damaged DNA. In Arabidopsis, both CRY1 and CRY2 are implicated in numerous blue light-dependent responses, including inhibition of hypocotyl elongation, leaf and cotyledon expansion, pigment biosynthesis, stem growth and internode elongation, control of flowering time and phototropism. No information about the in vivo function of CRY genes is available in other plant species. The tomato CRY1 gene (TCRY1) encodes a protein of 679 amino acids, which shows 78% identity and 88% similarity to Arabidopsis CRY1. In order to verify the in vivo function of TCRY1, we constructed antisense tomato plants using the C-terminal portion of the gene. Partial repression of both mRNA and protein levels was observed in one of the transformants. The progeny from this transformant showed an elongated hypocotyl under blue but not under red light. This character co-segregated with the transgene and was dependent on transgene dosage. An additional, partially elongated phenotype was observed in adult plants grown in the greenhouse under dim light and short days with no artificial illumination. This phenotype was suppressed by artificial illumination of both short and long photoperiods. The synthesis of anthocyanins under blue light was reduced in antisense seedlings. In contrast, carotenoid and chlorophyll levels and second positive phototropic curvature were essentially unaltered.