Clinical safety of 3-T brain magnetic resonance imaging in newborns

Background The effects and potential hazards of brain magnetic resonance imaging (MRI) at 3 T in newborns are debated. Objective Assess the impact of 3-T MRI in newborns on body temperature and physiological parameters. Material and methods Forty-nine newborns, born preterm and at term, underwent 3-T brain MRI at term-corrected age. Rectal and skin temperature, oxygen saturation and heart rate were recorded before, during and after the scan. Results A statistically significant increase in skin temperature of 0.6 \ub0C was observed at the end of the MRI scan (P<0.01). There was no significant changes in rectal temperature, heart rate or oxygen saturation. Conclusion Core temperature, heart rate and oxygen saturation in newborns were not affected by 3-T brain MR scanning

Matrix metalloproteinases and left ventricular function and structure in spinal cord injured subjects

Subjects with spinal cord injury (SCI) exhibit impaired left ventricular (LV) diastolic function, which has been reported to be attenuated by regular physical activity. This study investigated the relationship between circulating matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) and echocardiographic parameters in SCI subjects and the role of physical activity in this regard. Forty-two men with SCI [19 sedentary (S-SCI) and 23 physically-active (PA-SCI)] were evaluated by clinical, anthropometric, laboratory, and echocardiographic analysis. Plasmatic pro-MMP-2, MMP-2, MMP-8, pro-MMP-9, MMP-9, TIMP-1 and TIMP-2 levels were determined by enzyme-linked immunosorbent assay and zymography. PA-SCI subjects presented lower pro-MMP-2 and pro-MMP-2/TIMP-2 levels and improved markers of LV diastolic function (lower E/Em and higher Em and E/A values) than S-SCI ones. Bivariate analysis showed that pro-MMP-2 correlated inversely with Em and directly with E/Em, while MMP-9 correlated directly with LV mass index and LV end-diastolic diameter in the whole sample. Following multiple regression analysis, pro-MMP-2, but not physical activity, remained associated with Em, while MMP-9 was associated with LV mass index in the whole sample. These findings suggest differing roles for MMPs in LV structure and function regulation and an interaction among pro-MMP-2, diastolic function and physical activity in SCI subjects.Subjects with spinal cord injury (SCI) exhibit impaired left ventricular (LV) diastolic function, which has been reported to be attenuated by regular physical activity. This study investigated the relationship between circulating matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) and echocardiographic parameters in SCI subjects and the role of physical activity in this regard. Forty-two men with SCI [19 sedentary (S-SCI) and 23 physically-active (PA-SCI)] were evaluated by clinical, anthropometric, laboratory, and echocardiographic analysis. Plasmatic pro-MMP-2, MMP-2, MMP-8, pro-MMP-9, MMP-9, TIMP-1 and TIMP-2 levels were determined by enzyme-linked immunosorbent assay and zymography. PA-SCI subjects presented lower pro-MMP-2 and pro-MMP-2/TIMP-2 levels and improved markers of LV diastolic function (lower E/Em and higher Em and E/A values) than S-SCI ones. Bivariate analysis showed that pro-MMP-2 correlated inversely with Em and directly with E/Em, while MMP-9 correlated directly with LV mass index and LV end-diastolic diameter in the whole sample. Following multiple regression analysis, pro-MMP-2, but not physical activity, remained associated with Em, while MMP-9 was associated with LV mass index in the whole sample. These findings suggest differing roles for MMPs in LV structure and function regulation and an interaction among pro-MMP-2, diastolic function and physical activity in SCI subjects43713614

Variação sazonal na alelopatia de extratos aquosos de Coleus barbatus (A.) Benth. sobre a germinação e o desenvolvimento de Lactuca sativa L. Seasonal variation in the allelopathy of aqueous extracts from Coleus barbatus (A.) Benth. on the germination and development of Lactuca sativa L.

O objetivo deste trabalho foi avaliar o efeito alelopático de extratos de Coleus barbatus sobre a germinação e desenvolvimento de plântulas de alface. Os experimentos foram conduzidos em laboratório, em diferentes concentrações de extratos obtidos de folhas de falso-boldo (0; 7,5; 15; 22,5; 30%), coletadas nas quatro estações do ano, obtidos por trituração, maceração, infusão e decocção. As sementes de alface foram distribuídas sobre placas de petri umidecidas com 10 mL de solução. Os resultados mostraram que os extratos de folhas afetaram a germinabilidade de sementes de alface apenas na concentração de 30% do extrato preparado por decocção de folhas coletadas no inverno. O índice de velocidade de germinação apresentou redução significativa nos extratos triturados preparados no outono e inverno; na maceração de folhas coletadas no verão e outono e no extrato de decocção preparado no inverno. Os extratos estimularam o crescimento da parte aérea das plântulas de alface, ao passo que, o comprimento das raízes foi afetado pelos extratos, ora inibindo, ora estimulando o crescimento das mesmas. Os extratos de folhas de falso-boldo coletadas nas quatro estações do ano apresentaram efeito alelopático sobre a germinação e o desenvolvimento da alface, sendo que estes variaram em função da sazonalidade da coleta, da forma de obtenção dos extratos e das concentrações testadas.<br>The aim of this study was to evaluate the allelopathic effects of extracts from Coleus barbatus on germination and seedling growth of lettuce. The experiments were conducted in the laboratory using different concentrations (0, 7.5, 15, 22.5, 30%) of aqueous extracts from "falso-boldo" leaves harvested in all four seasons; extracts were obtained by grinding, maceration, infusion and decoction. Seeds were distributed on Petri dishes moistened with 10 mL solution. Results showed that the leaf extracts affected the germination of lettuce seeds only at the concentration of 30% extract prepared by decoction of leaves harvested in the winter. Germination speed index showed significant reduction for ground extracts prepared in the fall and winter, as well as for macerated leaves harvested in the summer and fall and for extracts prepared through decoction in the winter. The extracts stimulated the growth of shoots of lettuce seedlings, whereas root length was affected by the extracts, which either stimulated or inhibited its growth. Extracts of "falso-boldo" leaves harvested in all four seasons had allelopathic effect on germination and development of lettuce, and the latter varied depending on the harvest season, the form of preparing the extracts and the tested concentrations

Associações espaciais entre indivíduos de diferentes espécies de Miconia spp. Ruiz & Pav. (Melastomataceae)

Este estudo avaliou as associações espaciais de indivíduos pertencentes a todas as espécies arbóreas do gênero Miconia presentes no sub-bosque de um plantio experimental de espécies dos gêneros Eucalyptus e Corymbia. Como o gênero Miconia possui a maioria das espécies pioneiras, a hipótese testada foi de que os pares de espécies analisadas apresentam indivíduos com sobreposição total ou parcial de habitat. Considerando o histórico da área, é possível supor que todos os indivíduos se regeneraram a partir da chuva e do banco de sementes. Foi estabelecido um transecto cruzando a área de estudo no sentido de seu maior comprimento, a partir do qual foram determinadas as coordenadas dos indivíduos do gênero Miconia com DAS (diâmetro medido na altura do solo) maior ou igual a 1 cm. As associações espaciais entre os indivíduos das diferentes espécies foram analisadas por meio da função K de Ripley bivariada. Foram amostrados indivíduos de Miconia pepericarpa DC., Miconia sellowiana Naudin, Miconia albicans Triana, Miconia argyrophylla DC., Miconia chartacea Triana e Miconia cinnamomifolia (DC.) Naudin. De forma geral, os resultados demonstraram ausência de associação espacial negativa entre os pares das espécies, indicando que os indivíduos de Miconia spp. compartilham parcial ou totalmente o mesmo espaço no sub-bosque de um plantio de eucalipto. Os resultados obtidos, apesar de não poderem ser extrapolados para outras espécies, corroboram a ideia de que algumas espécies pioneiras tendem a coexistir, em florestas tropicais, em áreas onde há maior disponibilidade de luz