Multimodal approach to assess tumour vasculature and potential treatment effect with DCE-US and DCE-MRI quantification in CWR22 prostate tumour xenografts.

The aim of this study was to compare intratumoural heterogeneity and longitudinal changes assessed by dynamic contrast-enhanced ultrasound (DCE-US) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in prostate tumour xenografts. In vivo DCE-US and DCE-MRI were obtained 24 h pre- (day 0) and post- (day 2) radiation treatment with a single dose of 7.5 Gy. Characterization of the tumour vasculature was determined by Brix pharmacokinetic analysis of the time-intensity curves. Histogram analysis of voxels showed significant changes (p < 0.001) from day 0 to day 2 in both modalities for kep , the exchange rate constant from the extracellular extravascular space to the plasma, and kel , the elimination rate constant of the contrast. In addition, kep and kel values from DCE-US were significantly higher than those derived from DCE-MRI at day 0 (p < 0.0001) for both groups. At day 2, kel followed the same tendency for both groups, whereas kep showed this tendency only for the treated group in intermediate-enhancement regions. Regarding kep median values, longitudinal changes were not found for any modality. However, at day 2, kep linked to DCE-US was correlated to MVD in high-enhancement areas for the treated group (p = 0.05). In contrast, correlation to necrosis was detected for the control group in intermediate-enhancement areas (p < 0.1). Intratumoural heterogeneity and longitudinal changes in tumour vasculature were assessed for both modalities. Microvascular parameters derived from DCE-US seem to provide reliable biomarkers during radiotherapy as validated by histology. Furthermore, DCE-US could be a stand-alone or a complementary technique.

Salt and blood pressure in children and adolescents.

To study the relationship between salt intake and blood pressure in children and adolescents, we analysed the data of a large cross-sectional study (the National Diet and Nutrition Survey for young people), which was carried out in Great Britain in 1997 in a nationally representative sample of children aged between 4 and 18 years. A total of 1658 participants had both salt intake and blood pressure recorded. Salt intake was assessed by a 7-day dietary record. The average salt intake, which did not include salt added in cooking or at the table, was 4.7+/-0.2 g/day at the age of 4 years. With increasing age, there was an increase in salt intake, and by the age of 18 years, salt intake was 6.8+/-0.2 g/day. There was a significant association of salt intake with systolic blood pressure as well as with pulse pressure after adjusting for age, sex, body mass index and dietary potassium intake. An increase of 1 g/day in salt intake was related to an increase of 0.4 mm Hg in systolic and 0.6 mm Hg in pulse pressure. The magnitude of the association with systolic blood pressure is very similar to that observed in a recent meta-analysis of controlled trials where salt intake was reduced. The consistent finding of our present analysis of a random sample of free-living individuals with that from controlled salt reduction trials provides further support for a reduction in salt intake in children and adolescents.

Desenvolvimento do UMELISA-TSH neonatal para dosagem de TSH em sangue coletado em papel filtro / Development of the ultramicroelisa for determination of neonatal TSH from blood spots on filter paper

O hipotireoidismo congênito, causado pela ausência anatômica ou funcional da glândula tireóide, apresenta freqüência mundial de aproximadamente 1:4000 recém-nascidos. A principal implicação da doença, o retardo mental, somente pode ser evitada se o tratamento se iniciar nas primeiras semanas de vida. Por isso, o diagnóstico precoce constitui a chave de êxito no tratamento da enfermidade. O Umelisa – TSH neonatal é um ensaio heterogêneo imunoenziomático tipo sanduíche, cuja fase sólida são micropoços de 10mL em tiras/placas pré-sensibilizadas com anticorpos policlonais anticadeia Beta do TSH. As amostras de sangue são eluídas com um conjugado anti_TSH policlonal/fosfatase alcalina e transferidas para placas de reação. A reação é revelada com substrato fluorigênico e a intensidade da fluorescência emitida é proporcional à concentração de TSH presente na amostra. A leitura é realizada automaticamente por um leitor fluorímetro-fotômetro computadorizado. A curva padrão validada contra ao padrão 80 558 da OMS varia dentro de uma faixa de 10-200 µUI/L, com limite de detecção de 2 µUI/L. Posteriormente, a curva foi ajustada para medir valores a partir de 0,1 µUI/L. A avaliação analítica mostrou uma precisão intra e inter-ensaio no ponto de corte (25 µUI/L) de 6,2 e 7,4 por cento, respectivamente. A correlação entre o Umelisa – TSH neonatal e o Delfia neonatal TSH foi boa (r = 0,99), além de não ser detectadas interferências significativas com outros hormônios hipofisários e proteínas séricas. A recuperação do teste foi de 101,1 +/- 3,7 por cento. Na prova de paralelismo, as concentrações calculadas de 3 amostras, após a correção com o fator de diluição, foi de +/- 6,4 por cento da concentração original da amostra pura. O Umelisa- TSH neonatal mostrou-se um método rápido e sensível, podendo ser utilizado como uma opção para programas de rastreamento em massa, já que permite operar com grandes quantidades de amostras garantindo eficiência e custo compatível com a tabela de exames complementares do Sistema Único de Saúde (SUS).