Rapid, reliable and inexpensive quality assessment of biotinylated cRNA

The interpretation of oligonucleotide array experiments depends on the quality of the target cRNA used. cRNA target quality is assessed by quantitative analysis of the representation of 5' and 3' sequences of control genes using commercially available Test arrays. The Test array provides an economically priced means of determining the quality of labeled target prior to analysis on whole genome expression arrays. This manuscript validates the use of a duplex RT-PCR assay as a faster (6 h) and less expensive (6 were chosen and classified as degraded cRNAs, and 31 samples with a ß-actin 3'/5' ratio <6 were selected as good quality cRNAs. Blinded samples were then used for the RT-PCR assay. After gel electrophoresis, optical densities of the amplified 3' and 5' fragments of ß-actin were measured and the 3'/5' ratio was calculated. There was a strong correlation (r² = 0.6802) between the array and the RT-PCR ß-actin 3'/5' ratios. Moreover, the RT-PCR 3'/5' ratio was significantly different (P < 0.0001) between undegraded (mean ± SD, 0.34 ± 0.09) and degraded (1.71 ± 0.83) samples. None of the other parameters analyzed, such as i) the starting amount of RNA, ii) RNA quality assessed using the Bioanalyzer Chip technology, or iii) the concentration and OD260/OD280 ratio of the purified biotinylated cRNA, correlated with cRNA quality.

Conservation of glycolytic oscillations in Saccharomyces cerevisiae and human pancreatic b-cells: a study of metabolic robustness

The present study compares two computer models of the first part of glucose catabolism in different organisms in search of evolutionarily conserved characteristics of the glycolysis cycle and proposes the main parameters that define the stable steady-state or oscillatory behavior of the glycolytic system. It is suggested that in both human pancreatic b-cells and Saccharomyces cerevisiae there are oscillations that, despite differences in wave form and period of oscillation, share the same robustness strategy: the oscillation is not controlled by only one but by at least two parameters that will have more or less control over the pathway flux depending on the initial state of the system as well as on extra-cellular conditions. This observation leads to two important interpretations: the first is that in both S. cerevisiae and human b-cells, despite differences in enzyme kinetics and mechanism of feedback control, evolution seems to have kept an oscillatory behavior coupled to the glucose concentration outside the cytoplasm, and the second is that the development of drugs to regulate metabolic dysfunctions in more complex systems may require further study, not only determining which enzyme is controlling the flux of the system but also under which conditions and how its control is maintained by the enzyme or transferred to other enzymes in the pathway as the drug starts acting.

Quistes de Rafe medio genitoperineal / Genitoperineal median Raphe cysts

Los quistes del rafe medio representan defectos del desarrollo embriológico de la zona genitc cuentran tapizados por diferentes epitelios según su ubicación. Estas lesiones, que son más comúnmente hall ca del meato uretral, pueden localizarse en cualquier lugar del rafe medio genitoperineal, desde el glandi ano. El tratamiento de elección es la escisión quirúrgica. Presentamos tres nuevos casos y revisamos la literatura.

Polipo fibroepitelial del ureter: aporte de un nuevo caso: Revisión de la literatura / Fibroepithelial polyp of the ureter: case report: Review of the literature

Los pólipos fibroepiteliales son tumores benignos que se pueden manifestar a lo largo de todo el tracto urinario. Se presenta un caso de pólipo fibroepitelial en uréter. Revisamos la literatura y discutimos las características clínicas, diagnósticas y terapéuticas de esta rara entidad

Ocorrência, distribuição e toxicidade de cianobactérias no estuário da Lagoa dos Patos, RS / The occurrence, distribution and toxicity of cyanobacteria in the estuary of Lagoa dos Patos, Rio Grande do Sul

Diversas florações da cianobactéria Microcystis aeruginosa têm sido observadas nas águas do estuário da Lagoa dos Patos nos últimos 15 anos, sem o devido estudo de sua distribuição e ocorrência ou do risco de contaminação do ecossistema aquático. Neste estudo, foram realizadas a identificação e a quantificação das cianobactérias da região estuarina da Lagoa dos Patos, particularmente M. aeruginosa, incluindo um levantamento quali-quantitativo dos principais grupos microfitoplanctônicos em relação à sua distribuição geográfica no estuário. Evidenciou-se que, ao longo de 12 meses, Microcystis aeruginosa esteve presente na região estuarina, com valor máximo de 1,3.106cél.Lû1 em dezembro de 1994 e mínimo de 1,5.105 cél.Lû1 em agosto de 1995, evidenciando a região norte do estuário da Lagoa dos Patos como sua principal fonte de entrada. Os períodos de maior abundância celular e colonial dessa cianobactéria foram consistentes com os resultados obtidos para os níveis de clorofila-a nas águas de superfície. Foram realizados testes de toxicidade (DL50 - 24 h) em camundongos com os extratos das florações de M. aeruginosa e foram determinadas, através de HPLCûDAD, as concentrações e algumas das variantes da hepatotoxina microcistina. As florações de M. aeruginosa observadas foram consideradas altamente tóxicas, com concentrações celulares de toxinas atingindo valores maiores que 1 mg.mgû1 p.s. e DL50 - 24 h menores que 100 mg.Kgû1 p.c. Encontraram-se diversas variantes da toxina microcistina, sendo microcistinaûLR a principal.

Demonstration of anti-bradykinin compounds in callus cultures of Mandevilla velutina

Calluses from stems and leaves of Mandevilla velutina were grown in culture for 30,45 and 60 days. Thin-layer chromatography of ethyl acetate extracts of calluses from stems of M. velutina revealed the presence of 6 compounds. Two of them had RF values identical to those of the anti-bradykinin (BK) compounds MV8609 and MV8610 previously isolated from the natural plant. The ethyl acetate extract (20 to 80 microng/ml) from stem callus culture antagonized in a concentration-dependent and reversible manner contractions caused by BK (0.1-100 nM) in the isolated rat uterus. The extracts obtained from calluses cultured for 30,45 and 60 days were about 79-, 63-and 31-fold more potent, respectively, in antagonizing BK than the crude extract obtained from the rhizome of the plant

Evolucao da mortalidade infantil e mortalidade infantil proporcional no Brasil. / Evolution of infant mortality and its proportion in Brazil

O autor analisa a evolucao da mortalidade infantil e mortalidade infantil proporcional no Brasil de 1968 a 1977, atraves da analise dos dados oriundos das Secretarias de Saude das Unidades Federadas, da Fundacao Sistema Estadual de Analise da Dados, Divisao Nacional de Epidemiologia e Estatistica e IBGE. Os altos indices verificados para a mortalidade em criancas menores de 1 ano, a tendencia de aumento constatada para a decada analisada e a ocorrencia ainda em grandes proporcoes de obitos por causas evitaveis, permitem afirmar que o nivel de saude nao so continua insatisfatorio como esta piorando. Os dados sugerem que a mortalidade infantil e muito mais influenciada por fatores extra-setoriais do que pelos intra-setoriais