Valoración en niños de la aceptabilidad de antibióticos resistentes a beta-lactamasas / Assessment of the palatability of beta-lactamase-resistant antibiotics in children

Se evaluó la aceptabilidad de tres antibióticos conocidos por su resistencia a beta-lactamasas en una muestra integrada por niños. Los resultados fueron comparados con los obtenidos en adultos. La aceptabilidad al sabor de los antibióticos en suspensión fue calificada con base en una escala analógica de 10 cm. Tanto en niños como en adultos, se asignó la calificación más alta a la azitromicina. Las significativas diferencias entre los sabores sugieren que este factor debe ser tomado en cuenta en todo estudio de aceptabilidad

Cytotoxic activity of a methanol extract of Phallusia nigra (Tunicata, Ascidiacea)

Tunicates have been reported to be a rich source of biologically active compounds. In this study, we demonstrate the presence of cytotoxic substances in Phallusia nigra, a common tunicate from Brazilian coastal waters. An extract of tunicate tissue was obtained by homogenizing the visceral organs from 50 specimens in methanol, followed by filtration and concentration in a rotary vacuum evaporator. Finally, the concentrate was partitioned with chloroform to remove lipids. The resulting extract possessed antimitotic and hemolytic activity. The former was demonstrated as a delay in the development of sea urchin eggs by partially inhibiting the process of cleavage (first cleavage, EC50 ñ SEM = 3.44 ñ 0.84 mg/ml). The <500 molecular fraction of the extract obtained by ultrafiltration also inhibited cell proliferation (the number of viable cells was decreased by 68 per cent with 500 mug/ml) and DNA synthesis of T47D cells derived from human breast carcinoma as measured by [3H]-thymidine incorporation (66 per cent of the control value after 24-h incubation with 100 mug/ml). Dose-dependent hemolysis obtained with P. nigra extract on mouse erythrocytes had an EC50 ñ SEM = 1.12 ñ 0.02 mglml for a 0.5 per cent erythrocyte suspension. Hemolysis could be reduced by pre-incubating the cells with choline-containing phospholipid. Sphingomyelin (40 mug/ml) increased the EC50 by twofold to 2.86 ñ 0.04 mg/ml, but phosphatidylcholine (80 mug/ml) did not modify hemolysis.