"In vivo" and "in vitro" antitumoral action of Larrea divaricata cav

We previously reported that aqueous extract of Larrea divaricata Cav had an antiproliferative activity upon tumoral lymphoid cells (BW 5147), without affecting normal immunity. To determine the probable mechanism of the inhibitory action of the extract upon cell growth, the participation of intracellular signals involved in the inhibition of cell proliferation, namely the activation of adenylate cyclase system was studied. The production of cyclic 3, 5 adenosine monophosphate (cAMP) in presence and absence of extract was analized. The extract increased the cAMP levels, but neither the cAMP production nor the inhibitory effect of the extract on proliferation were blocked by a beta adrenergic receptor antagonist (propranolol) or by histaminergic receptor antagonistis (cimetidine and mepyramine). So, we concluted that the antiproliferative activity of the extract of BW 5147 cells would be mediated by an increase in cAMP intracellular levels no related to the activation of the membrane receptors here studied. In parallel, the extract was administered to a pregnant rat with a spontaneous mammarian carcinoma and "in vivo"antitumoral activity was found. (AU)

Braquiterapia de tumores sólidos: uso del fosfato crómico coloidal / Brachytherapy of solid tumors: use of chromic phosphate coloid

Con el propósito de evaluar la efectividad de una dosis única de [33P]-Fosfato Crómico (Phosphocol(TM)) para el tratamiento de tumores sólidos, se realizaron estudios de bioeliminación, biodistribución y acción terapéutica en ratas portadoreas de tumores experimentales químicamente inducidos. Los resultados demuestran que el porcentaje de eliminación total es de 29.76 + 9.60 por ciento, siendo la eliminación por vía fecal de 23.28 + 8.81 por ciento y la urinaria de 6.48 + 2.11 por ciento. Los estudios de biodistribución revelan que el 51.61 + 5.82 por ciento de la actividad inyectada se encuentra en el tumor, mientras que en órganos donde existen células reticuloendoteliales, se encontró que el porcentaje de actividad es de 13.09 + 5.15 por ciento en hígado y de 2.88 + 1.23 por ciento en pulmón. Por otra parte, los estudios de acción terapéutica demuestran que el porcentaje de regresión tumoral (P.R.T.) es de 61.0 por ciento para los tumores inyectados. Cabe destacar que 4 de los animales tratados mostraron perfiles de bioeliminación, en los cuales, la misma aumentó abruptamente en algún momento del estudio. Estos resultados demuestran que no es recomendable el uso de este tipo de coloides en el tratamiento de tumores sólidos con moderado grado de vascularización, debido a que puede existir movilización del mismo y en consecuencia iradiación de otros órganos no afectados al tratamiento. (AU)

Bioavailability of microencapsulated ferrous sulfate in fluid milk studies in human beings

Iron deficiency is one of the most important nutritional problems in the world. The best method to overcome this problem is the fortification of foods with highly bioavailable iron. Fluid milk is a massive consumption food with an easy access and which is generally the only food intake during the first months of life. Therefore the fortification of fluid milk with highly biovalable iron and no detectable alterations of its sensorial characteristics was studied in the present work. This procedure was made possible using a new type of ferrous sulfate, stabilized and microencapsulated with soy lecithin (SFE-171). The iron concentration of the fortified milk is 12 mg per liter. In order study the iron absorption from milk fortifield with this product, SFE-171 was labeled with59 Fe and given to 29 volunteers with a normal iron status, each of which received an iron quantily of 3 mg in 250 ml of fluid milk. The average iron absorption was (10.2+4.7) per cent. This result shows that the iron given in this physiocochemical form has the advantage of a high biovailability and it is possible that this product will be the first attempt for an adequate solution of iron deficiency. (AU)